Photosensitive film

Abstract

To provide a photosensitive film which is excellent in undercut resistance.SOLUTION: A photosensitive film includes a support, and a photosensitive resin composition layer provided on the support. The photosensitive resin composition layer has a first photosensitive resin composition layer formed of a first photosensitive resin composition, and a second photosensitive resin composition layer which is provided on the first photosensitive resin composition layer and is formed of a second photosensitive resin composition in this order from the support side. The first and second photosensitive resin compositions each contain (A) one or more kinds of resins selected from the group consisting of polyimide and a polyimide precursor, (B) a photo-radical generator, and (C) a photo-crosslinking agent. A difference between absorbance of the second photosensitive resin composition layer and absorbance of the first photosensitive resin composition layer is 0.05 or more and 0.5 or less.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a photosensitive film, a method for manufacturing a semiconductor package substrate using the same, a semiconductor package substrate, and a semiconductor device. [Background technology]

[0002] Conventionally, negative-type photosensitive resin compositions containing a photosensitive polyimide resin or its precursor, which exhibit excellent heat resistance and insulation properties, have been used as insulating layers in semiconductor devices (see, for example, Patent Document 1). Furthermore, in recent years, with the increasing speed and capacity of communications in communication equipment, there is a demand for excellent resolution in photosensitive resin compositions used for forming insulating layers in semiconductor package substrates of communication equipment, or for redistribution layers in wafer-level packages (WLPs), etc. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2003-084435 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] On the other hand, there are cases where it is desirable to form an insulating layer containing polyimide resin with a thicker film. However, negative-type photosensitive resin compositions are generally known to have low resolution, and when forming holes (via holes) in an insulating layer with a particularly thick film, the problem of the via hole's cross-section becoming inversely tapered due to the reduced resolution of the lower layer becomes more apparent.

[0005] Specifically, exposure generally causes radical crosslinking to progress from the exposed surface of the photosensitive resin composition layer, and the progression of radical crosslinking decreases as the distance from the exposed surface of the photosensitive resin composition layer increases. If the progression of crosslinking is insufficient, the solubility in the developer will be poor. Therefore, in a cross-section of the photosensitive resin composition layer cut in the thickness direction, the cross-sectional shape of the hole will be an inverse taper, where the diameter of the bottom formed at the deepest point is larger than the diameter of the opening formed at the exposed surface. This can be particularly noticeable when the thickness of the photosensitive resin composition layer is thick. In this case, the difference between the radius of the opening corresponding to the top of the hole and the radius of the bottom corresponding to the deepest point of the hole (bottom radius - top radius) is called "undercut," and the property of the opening shape not easily becoming an inverse taper is sometimes referred to as having "excellent undercut resistance."

[0006] The present invention was devised in view of the above-mentioned problems, and aims to provide a photosensitive film that can produce a cured product with excellent undercut resistance; a method for manufacturing a semiconductor package substrate using a photosensitive film; and a semiconductor package substrate and a semiconductor device. [Means for solving the problem]

[0007] The inventors diligently studied to solve the aforementioned problems. As a result, the inventors found that the aforementioned problems can be solved by adjusting the first photosensitive resin composition constituting the first photosensitive resin composition layer, and the second photosensitive resin composition containing (A) one or more resins selected from the group consisting of polyimide and polyimide precursors, (B) a photoradical generator, and (C) a photocrosslinking agent, such that the difference in absorbance between the first and second photosensitive resin composition layers is 0.05 or more and 0.5 or less, and thus completed the present invention. That is, the present invention includes the following.

[0008] [1] Support and A photosensitive film comprising a photosensitive resin composition layer provided on a support, The photosensitive resin composition layer comprises a first photosensitive resin composition layer made of a first photosensitive resin composition, and a second photosensitive resin composition layer made of a second photosensitive resin composition provided on the first photosensitive resin composition layer, in this order from the support side. The first and second photosensitive resin compositions are, (A) One or more resins selected from the group consisting of polyimides and polyimide precursors, (B) Photoradical generators, and (C) Contains a photocrosslinking agent, A photosensitive film in which the difference between the absorbance of the second photosensitive resin composition layer and the absorbance of the first photosensitive resin composition layer (absorbance of the second photosensitive resin composition layer - absorbance of the first photosensitive resin composition layer) is 0.05 or more and 0.5 or less. [2] The photosensitive film according to [1], wherein component (A) contains a structural unit represented by the following formula (A-1). [ka] (In the formula, A independently represents a tetravalent organic group, B represents a divalent organic group, and R 1 and R 2 Each of these independently represents a hydrogen atom or a monovalent organic group. [3] R in equation (A-1) 1 and R 2 The photosensitive film according to [2], wherein each of the groups is independently at least one radical-reactive group. [4] The photosensitive film described in [3], wherein each radical-reactive group is independently represented by the following formula (A-2). [ka] (In equation (A-2), R 4a , R 5a and R 6a Each of the following independently represents a hydrogen atom or an aliphatic hydrocarbon group with 1 to 3 carbon atoms, and X represents a divalent organic group. * represents a bond. [5] The photosensitive film according to any one of [1] to [4], wherein the component (B) contains a photo radical generator rich in reactivity (B-1) and a photo radical generator excellent in deep part curability (B-2). [6] The photosensitive film according to any one of [1] to [5], wherein the content of the component (B) contained in the first photosensitive resin composition is less than the content of the component (B) contained in the second photosensitive resin composition. [7] The photosensitive film according to any one of [1] to [6], wherein the content of the component (B) in the first photosensitive resin composition is 0.03 parts by mass or more and 5 parts by mass or less with respect to 100 parts by mass of the component (A) in the first photosensitive resin composition. [8] The photosensitive film according to any one of [1] to [7], wherein the content of the component (B) in the second photosensitive resin composition is 0.05 parts by mass or more and 8 parts by mass or less with respect to 100 parts by mass of the component (A) in the second photosensitive resin composition. [9] The photosensitive film according to any one of [1] to [8], wherein the absorbance of the first photosensitive resin composition layer is 0.2 or more and 1.5 or less.

[10] The photosensitive film according to any one of [1] to [9], wherein the absorbance of the second photosensitive resin composition layer is 0.3 or more and 1.5 or less.

[11] Let the content of the component (B-1) in the first photosensitive resin composition be b when the non-volatile component of the first photosensitive resin composition is 100% by mass. 1-1 Let the content of the component (B-1) in the second photosensitive resin composition be b 2-1 When, b 1-1 / b 2-1 is 0.1 or more and 3 or less, the photosensitive film according to any one of [1] to

[10] .

[12] A semiconductor package substrate including an insulating layer containing a cured product of a photosensitive resin composition layer of the photosensitive film according to any one of [1] to

[11] .

[13] A semiconductor device including the semiconductor package substrate according to

[12] .

[14] A step of laminating a photosensitive resin composition layer of the photosensitive film according to any one of [1] to

[11] on a circuit board, A step of irradiating the photosensitive resin composition layer with actinic rays, A method for manufacturing a semiconductor package substrate, comprising the step of developing a photosensitive resin composition layer.

[15] A step of applying a second photosensitive resin composition onto a circuit board to form a second photosensitive resin composition layer, A step of applying a first photosensitive resin composition onto a second photosensitive resin composition layer to form a first photosensitive resin composition layer, A step of irradiating the first and second photosensitive resin composition layers with active light, A method for manufacturing a semiconductor package substrate, comprising the step of developing first and second photosensitive resin composition layers, The first and second photosensitive resin compositions are (A) One or more resins selected from the group consisting of polyimides and polyimide precursors, (B) Photoradical generators, and (C) Contains a photocrosslinking agent, A method for manufacturing a semiconductor package substrate, wherein the difference in absorbance between a first photosensitive resin composition layer and a second photosensitive resin composition layer is 0.05 or more and 0.5 or less. [Effects of the Invention]

[0009] According to the present invention, a photosensitive film that can produce a cured product with excellent undercut resistance; a method for manufacturing a semiconductor package substrate using a photosensitive film; and a semiconductor package substrate and a semiconductor device can be provided. [Modes for carrying out the invention]

[0010] The present invention will be described in detail below with reference to embodiments and examples. However, the present invention is not limited to the embodiments and examples listed below, and may be implemented with modifications as appropriate without departing from the scope of the claims and their equivalents.

[0011] [Photosensitive film] The photosensitive film of the present invention comprises a support and a photosensitive resin composition layer provided on the support, wherein the photosensitive resin composition layer has, in this order from the support side, a first photosensitive resin composition layer made of a first photosensitive resin composition and a second photosensitive resin composition layer made of a second photosensitive resin composition provided on the first photosensitive resin composition layer, and the first and second photosensitive resin compositions each contain (A) one or more resins selected from the group consisting of polyimide and polyimide precursors, (B) a photoradical generator, and (C) a photocrosslinking agent, and the difference between the absorbance of the second photosensitive resin composition layer and the absorbance of the first photosensitive resin composition layer is 0.05 or more and 0.5 or less. By using such a photosensitive film, a cured product with excellent undercut resistance can be obtained. In addition, it is usually possible to obtain a cured product with excellent limiting resolution and excellent adhesion to copper foil.

[0012] The photosensitive film of the present invention comprises a support, a first photosensitive resin composition layer, and a second photosensitive resin composition layer in that order. Therefore, when the photosensitive resin composition layer is laminated onto a laminated member such as a circuit board, the second photosensitive resin composition layer is bonded to the laminated member. Thus, when forming a hole in the photosensitive resin composition layer, the second photosensitive resin composition layer is located at the deepest part of the hole. In the present invention, the difference between the absorbance of the second photosensitive resin composition layer and the absorbance of the first photosensitive resin composition layer is 0.05 or more and 0.5 or less. Therefore, the absorbance of the second photosensitive resin composition layer is greater than that of the first photosensitive resin composition layer. Consequently, the second photosensitive resin composition layer undergoes crosslinking by radicals at the same rate as the first photosensitive resin composition layer, resulting in excellent undercut resistance even with a thicker film thickness of the photosensitive resin composition layer.

[0013] The photosensitive resin composition layer of the aforementioned photosensitive film can be used as a positive-type photosensitive resin composition or a negative-type photosensitive resin composition layer, but from the viewpoint of undercut resistance, it is preferable to be a negative type. Therefore, the first and second photosensitive resin compositions constituting the photosensitive resin composition layer can be used as negative-type photosensitive resin compositions.

[0014] <Support> The photosensitive film comprises a support, on which a first photosensitive resin composition layer is formed.

[0015] Examples of support materials include polyethylene terephthalate film (PET film), polyethylene naphthalate film, polypropylene film, polyethylene film, polyvinyl alcohol film, and triacetyl acetate film, with polyethylene terephthalate film being particularly preferred.

[0016] Examples of commercially available supports include, but are not limited to, polypropylene films such as "Alfan MA-410" and "E-200C" from Oji Paper Co., Ltd., "GF-1" and "GF-8" from Tamapoly Co., Ltd., and polypropylene films from Shin-Etsu Film Co., Ltd.; and polyethylene terephthalate films such as the PS series, including "PS-25," from Teijin Corporation. These supports are preferably coated with a release agent, such as a silicone coating agent or a non-silicone coating agent, on their surface to facilitate removal. An example of a support whose surface has been treated with such a release agent is "AL-5" from Lintec Corporation.

[0017] The thickness of the support is preferably in the range of 5 μm to 100 μm, and more preferably in the range of 10 μm to 50 μm.

[0018] <Photosensitive resin composition layer> The photosensitive film comprises a photosensitive resin composition layer. The photosensitive resin composition layer comprises, in order from the support side, a first photosensitive resin composition layer and a second photosensitive resin composition layer. The first photosensitive resin composition layer contains a first photosensitive resin composition, and the second photosensitive resin composition layer contains a second photosensitive resin composition, and these layers differ in the type of components and / or their blending ratio such that the difference in absorbance between the first and second photosensitive resin composition layers is 0.01 or more and 0.5 or less.

[0019] The absorbance of the first photosensitive resin composition layer is preferably 0.2 or higher, more preferably 0.3 or higher, even more preferably 0.33 or higher, or 0.35 or higher, and preferably 1.5 or lower, more preferably 1.3 or lower, and even more preferably 1.2 or lower. The absorbance is measured at 365 nm, and the details of the absorbance measurement can be measured by the method described in the examples below.

[0020] The absorbance of the second photosensitive resin composition layer is preferably 0.3 or higher, more preferably 0.33 or higher, even more preferably 0.35 or higher, preferably 1.5 or lower, more preferably 1.3 or lower, and even more preferably 1.2 or lower. The absorbance is measured at 365 nm, and the details of the absorbance measurement can be measured by the method described in the examples below.

[0021] The difference between the absorbance of the second photosensitive resin composition layer and the absorbance of the first photosensitive resin composition layer (absorbance of the second photosensitive resin composition layer - absorbance of the first photosensitive resin composition layer) is 0.05 or more, preferably 0.06 or more, and more preferably 0.07 or more. The upper limit is 0.5 or less, preferably 0.45 or less, and more preferably 0.4 or less. The difference between the absorbance of the second photosensitive resin composition layer and the absorbance of the first photosensitive resin composition layer can be adjusted to this range, for example, by adjusting either (A) one or more types and amounts of resins selected from the group consisting of polyimide and polyimide precursors, and (B) the type and amount of photoradical generators contained in the first and second photosensitive resin composition layers. In particular, it is easy to adjust to this range by adjusting either (B) the type and amount of photoradical generators contained in the first and second photosensitive resin composition layers.

[0022] The thickness of the first photosensitive resin composition layer is preferably 10 μm or more, more preferably 15 μm or more, even more preferably 20 μm or more, preferably 100 μm or less, more preferably 75 μm or less, and even more preferably 50 μm or less.

[0023] The thickness of the second photosensitive resin composition layer is preferably 10 μm or more, more preferably 15 μm or more, even more preferably 20 μm or more, preferably 100 μm or less, more preferably 75 μm or less, and even more preferably 50 μm or less.

[0024] The thickness of the photosensitive resin composition layer (the total thickness of the first photosensitive resin composition layer and the second photosensitive resin composition layer; hereinafter sometimes referred to as "film thickness") is preferably 20 μm or more, more preferably 30 μm or more, even more preferably 40 μm or more, particularly preferably 50 μm or more, preferably 150 μm or less, more preferably 120 μm or less, even more preferably 100 μm or less, and particularly preferably 80 μm or less.

[0025] The first photosensitive resin composition layer contains the first photosensitive resin composition, and the second photosensitive resin composition layer contains the second photosensitive resin composition. The first and second photosensitive resin compositions each contain (A) one or more resins selected from the group consisting of polyimides and polyimide precursors, (B) a photoradical generator, and (C) a photocrosslinking agent. Hereinafter, the one or more resins selected from the group consisting of (A) polyimides and polyimide precursors may be referred to as "polyimide-based resins".

[0026] The first and second photosensitive resin compositions may optionally further contain (D) other additives and (E) solvents. The components that may be included in the first and second photosensitive resin compositions are described below.

[0027] In the following description, the term “may have substituents” when referring to a compound or group means, unless otherwise specified, both cases where the hydrogen atoms of the compound or group are not substituted with substituents, and cases where some or all of the hydrogen atoms of the compound or group are substituted with substituents.

[0028] In the following explanation, unless otherwise specified, the term "organic group" refers to a group that contains at least one carbon atom as a skeletal atom, and may be linear, branched, or cyclic.

[0029] -(A) Polyimide resin- The first and second photosensitive resin compositions each contain, as component (A), one or more resins (polyimide-based resins) selected from the group consisting of (A) polyimide and polyimide precursors. The polyimide in component (A) is a resin containing multiple imide structures within its molecule. The polyimide precursor in component (A) is a resin that can form polyimide by ring closure upon heating. By using component (A), the critical resolution of the photosensitive film can be improved.

[0030] Component (A) may be used alone or in combination of two or more types. Therefore, component (A) may contain only polyimide, only polyimide precursor, or a combination of polyimide and polyimide precursor. Among these, component (A) is preferably polyimide precursor from the viewpoint of critical resolution.

[0031] As a polyimide precursor, a resin containing multiple structural units selected from the group consisting of amic acid structural units and amic acid ester structural units may be used. An amic acid structural unit refers to a structural unit having a structure obtained by reacting a carboxylic acid dianhydride with a diamine compound. Amic acid structural units usually contain a carboxyl group. An amic acid ester structural unit refers to a structural unit having a structure obtained by esterifying some or all of these carboxyl groups, or a structural unit having a structure obtained by reacting some or all of these carboxyl groups with the epoxy group of an epoxy compound containing an ethylenically unsaturated bond. An ethylenically unsaturated bond refers to a non-aromatic carbon-carbon unsaturated bond, such as a non-aromatic carbon-carbon double bond and a carbon-carbon triple bond.

[0032] From the viewpoint of improving critical resolution, the polyimide precursor preferably contains an indan skeleton in the polyamic acid ester structural unit. The indan skeleton represents the skeleton shown in the following formula (a1-1). When the polyamic acid ester structural unit contains an indan skeleton, the solubility of the unexposed portion of the photosensitive resin composition layer in the developer can be increased. Therefore, the development time can be shortened, and more preferably, the resolution can be improved. Unless otherwise specified, "resolution" refers to the property of being able to form small-diameter holes in the photosensitive resin composition by exposure and development. Generally, the smaller the diameter of the holes that can be formed, the better the resolution. Among these, the polyimide precursor preferably contains a trimethylindan skeleton shown in the following formula (a1-2). The polyamic acid ester structural unit preferably contains the indan skeleton in the structural portion derived from the diamine compound. [ka]

[0033] A carboxylic acid dianhydride refers to a dianhydride of a carboxylic acid containing two acid anhydride groups (i.e., -CO-O-CO-) and an aliphatic or aromatic carbon bonded to these acid anhydride groups. Specific examples of carboxylic acid dianhydrides include aliphatic acid dianhydrides and aromatic acid dianhydrides. An aliphatic acid dianhydride refers to a dianhydride of a carboxylic acid containing two acid anhydride groups and an aliphatic carbon bonded to these acid anhydride groups. An aromatic acid dianhydride refers to a dianhydride of a carboxylic acid containing two acid anhydride groups and an aromatic carbon bonded to these acid anhydride groups. Specific examples of aliphatic acid dianhydrides include aliphatic tetracarboxylic acid dianhydrides. Specific examples of aromatic acid dianhydrides include aromatic tetracarboxylic acid dianhydrides. These tetracarboxylic acid dianhydrides may be used individually or in combination of two or more types.

[0034] In aliphatic dianhydrides, the aliphatic carbons are usually saturated aliphatic carbons. Preferably, the acid anhydride groups are bonded to saturated aliphatic chains, and a ring structure is formed by the bonded acid anhydride groups and saturated aliphatic chains. This ring structure is usually a heterocycle consisting of an oxygen atom and a carbon atom, and is preferably a 5-membered or 6-membered ring, with a 5-membered ring being more preferable. In addition, aliphatic dianhydrides may contain unsaturated aliphatic chains and aromatic chains in parts other than the sites to which the acid anhydride groups are directly bonded.

[0035] The molecular weight of the aliphatic acid dianhydride is preferably 400 or less. By keeping the molecular weight within this range, swelling of the first photosensitive resin composition layer during development can be suppressed, and the residual film rate can be effectively increased.

[0036] Examples of aliphatic acid dianhydrides include 1,2,4,5-cyclohexanetetracarboxylic acid dianhydride, bicyclo[2.2.2]octo-7-ene-2,3,5,6-tetracarboxylic acid dianhydride, bicyclo[2.2.1]heptane-2-endo-3-endo-5-exo-6-exo-2,3,5,6-tetracarboxylic acid dianhydride, bicyclo[2.2.1]heptane-2-exo-3-exo-5-exo-6-exo- Examples include 2,3,5,6-tetracarboxylic dianhydride, bicyclo[2.2.1]heptane-2,3,5,6-tetracarboxylic dianhydride, 2-(3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthyl)succinic dianhydride, 5-(2,5-dioxotetrahydrofuryl)-3-methyl-3-cyclohexen-1,2-dicarboxylic anhydride, and 1,2,3,4-butanetetracarboxylic dianhydride. Among these, 2-(3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthyl)succinic dianhydride, 5-(2,5-dioxotetrahydrofuryl)-3-methyl-3-cyclohexen-1,2-dicarboxylic anhydride, and 1,2,3,4-butanetetracarboxylic dianhydride are particularly noteworthy.

[0037] Specific examples of aromatic acid dianhydrides include, for example, 4,4'-oxydiphthalic acid dianhydride, 3,3',4,4'-benzophenonetetracarboxylic acid dianhydride, pyromellitic acid dianhydride, 3,4,9,10-perylenetetracarboxylic acid dianhydride, 3,3',4,4'-diphenylsulfonetetracarboxylic acid dianhydride, 3,3',4,4'-biphenyltetracarboxylic acid dianhydride, 1,2,5,6-naphthalenetetracarboxylic acid dianhydride, 3,3',4,4'-paraterphenyltetracarboxylic acid dianhydride, 3,3',4,4'-methaterphenyltetracarboxylic acid dianhydride, and decahydro-dimethanonaphthalenetetracarboxylic acid dianhydride.

[0038] Examples of diamine compounds include bis[2-(3-aminopropoxy)ethyl] ether, 1,4-butanediol-bis(3-aminopropyl) ether, 3,9-bis(3-aminopropyl)-2,4,8,10-tetraspiro-5,5-undecane, 1,2-bis(2-aminoethoxy)ethane, 1,2-bis(3-aminopropoxy)ethane, triethylene glycol-bis(3-aminopropyl) ether, polyethylene glycol-bis(3-aminopropyl) ether, 3,9-bis(3-aminopropyl)-2,4,8,10-tetraspiro-5,5-undecane, and 1,4-butanediol-bis(3-aminopropyl) ether. Diamine compounds may be used individually or in combination of two or more. Diamine compounds containing aromatic rings may also be used. In particular, it is preferable that the diamine compound contains an indane skeleton. Examples of diamine compounds containing an indane skeleton include the diamine compounds shown in the following formulas (a2-1) to (a2-10). Among these, the diamine compounds shown in formulas (a2-4) to (a2-7) are preferred, and the diamine compound shown in formula (a2-4) is even more preferred. [ka]

[0039] As epoxy compounds containing ethylenically unsaturated bonds, compounds containing both ethylenically unsaturated bonds and epoxy groups can be used. The epoxy group may be included as a glycidyl group. Examples of epoxy compounds containing ethylenically unsaturated bonds include glycidyl acrylate, glycidyl methacrylate, 4-hydroxybutyl acrylate glycidyl ether, and 3,4-epoxycyclohexylmethyl methacrylate. Epoxy compounds containing ethylenically unsaturated bonds may be used individually or in combination of two or more types.

[0040] It is preferable that the polyimide precursor contains a radical-reactive group in its molecule. A radical-reactive group is a reactive group that can undergo polymerization by radicals generated by heat or light, and examples include groups containing non-aromatic carbon-carbon unsaturated bonds. When a polyimide precursor containing a radical-reactive group is used, the polyimide precursor can be crosslinked by exposure, effectively reducing the solubility of the photosensitive resin composition layer in the developer. The radical-reactive group may, for example, be contained in the esterified portion of an amic acid ester structural unit.

[0041] Furthermore, if the polyamic acid ester structural unit is a structural unit having a structure obtained by reacting some or all of the carboxyl groups with the epoxy groups of an epoxy compound containing ethylenically unsaturated bonds, then since the epoxy compound contains ethylenically unsaturated bonds, the epoxy compound residues may also contain ethylenically unsaturated bonds. Therefore, the epoxy compound residues can function as radical-reactive groups.

[0042] One embodiment of the polyimide precursor is preferably one that contains a structural unit represented by the following formula (A-1). [ka] (In formula (A-1), A represents a tetravalent organic group, B represents a divalent organic group, and R 1 and R 2Each of these independently represents a hydrogen atom or a monovalent organic group.

[0043] In formula (A-1), A represents a tetravalent organic group. The number of carbon atoms in A is preferably 6 to 40. Examples of tetravalent organic groups include tetravalent organic groups containing aliphatic hydrocarbon groups and tetravalent organic groups containing aromatic hydrocarbon groups.

[0044] The aliphatic hydrocarbon group contained in the tetravalent organic group contains an aliphatic carbon, to which the carbonyl group shown in formula (A-1) is bonded. The aliphatic carbon is usually a saturated aliphatic carbon. Preferably, the tetravalent organic group contains a saturated aliphatic chain, to which the carbonyl group shown in formula (A-1) is bonded. This saturated aliphatic chain preferably contains a carbon chain having 2 or 3 carbon atoms that links the two carbonyl groups shown in formula (A-1), and preferably contains a carbon chain having 2 carbon atoms. A saturated aliphatic chain containing a carbon chain having 2 carbon atoms that links the two carbonyl groups shown in formula (A-1) can be obtained by reacting an aliphatic acid dianhydride containing an acid anhydride group that forms a 5-membered ring with a diamine compound. Furthermore, a saturated aliphatic chain containing a carbon chain with 3 carbon atoms linking the two carbonyl groups shown in formula (A-1) can be obtained by reacting an aliphatic dianhydride containing an acid anhydride group that forms a 6-membered ring with a diamine compound.

[0045] An aromatic hydrocarbon group contains an aromatic compound, to which a carbonyl group shown in (A-1) above is bonded. For details, see the -COOR in formula (A-1) above. 1 Base and -COOR 2 Aromatic groups in which the -CONH- group and the -CONH- group are in the ortho position relative to each other, or alicyclic aliphatic groups (R 1 and R 2 R in equation (A-1) 1 and R 2 It is the same as ( ). Other examples include:

[0046] One embodiment of A is, for example, a tetravalent aliphatic hydrocarbon group which may have substituents. The tetravalent aliphatic hydrocarbon group may be a saturated aliphatic hydrocarbon group or an unsaturated aliphatic hydrocarbon group. Furthermore, the tetravalent aliphatic hydrocarbon group may be a linear hydrocarbon group, a cyclic hydrocarbon group (i.e., an alicyclic hydrocarbon group), or a combination thereof. In addition, the linear hydrocarbon group may be either linear or branched. Among these, the tetravalent aliphatic hydrocarbon group is preferably one which contains an aliphatic carbocyclic ring, and more preferably one which has a carbonyl group shown in formula (A-1) bonded to this aliphatic carbocyclic ring. The number of carbonyl groups bonded to the aliphatic carbocyclic ring is preferably two or more.

[0047] Examples of substituents that the tetravalent organic group in A may have include linear, branched, or cyclic alkyl groups having 1 to 10 carbon atoms, such as methyl, ethyl, propyl, and n-butyl groups; alkenyl groups such as vinyl, allyl, propenyl, and butenyl groups; halogen atoms such as fluorine, chlorine, and bromine atoms; alkoxy groups having 1 to 10 carbon atoms, such as methoxy, ethoxy, and propoxy groups; hydroxyl groups; halogen-substituted alkyl groups such as trifluoromethyl groups; and so on. These substituents may be bonded together to form a ring. The above substituents may have further substituents (hereinafter sometimes referred to as "secondary substituents"). There may be one substituent or two or more substituents.

[0048] The formula weight of A is preferably in the range of 328 or less. When the formula weight of A is within this range, swelling of the photosensitive resin composition during development can usually be suppressed, and the residual film rate can be effectively increased.

[0049] Examples of A include the groups shown in equations (a3-1) to (a3-12) below. In the equations, * represents a bond. [ka]

[0050] In formula (A-1), B represents a divalent organic group. The divalent organic group may contain an aromatic ring. It is preferable that the divalent organic group contains an aromatic ring. The divalent organic group may also contain an indane skeleton. In addition to the indane skeleton, the divalent organic group may further contain an aromatic ring.

[0051] Examples of divalent organic groups represented by B include the groups (a4-1) to (a4-30) shown below. Alternatively, groups formed by combining two or more of the (a4-1) to (a4-30) groups may be used as divalent organic groups. Among these, the groups (a4-2) and (a4-21) to (a4-30) are preferred for B, the groups (a4-2) and (a4-24) to (a4-27) are more preferred, and the group (a4-2) or (a4-24) is even more preferred. In the formula, * represents a bond. [ka] [ka] [ka] [ka]

[0052] The divalent organic group described above may have substituents. Examples of substituents are the same as those that may be present on a tetravalent organic group. There may be one substituent or two or more substituents.

[0053] In equation (A-1), R 1 and R 2Each of these independently represents a hydrogen atom or a monovalent organic group. Examples of monovalent organic groups include radical-reactive groups and saturated aliphatic groups having 1 to 4 carbon atoms, with radical-reactive groups being preferred. As radical-reactive groups, for example, groups containing ethylenically unsaturated bonds may be used. Specific examples of radical-reactive groups include vinyl groups, allyl groups, propagyl groups, ethynyl groups, phenylethynyl groups, butenyl groups, maleimide groups, nadiimide groups, (meth)acryloyl groups, and the group represented by formula (A-2) described later. "(meth)acryloyl group" includes methacryloyl groups, acryloyl groups, and combinations thereof. R in formula (A-1) 1 and R 2 Preferably, at least one of each group is a radical reactive group, and more preferably, both are radical reactive groups.

[0054] As the radical-reactive group, the group represented by the following formula (A-2) is preferred. Therefore, R 1 and R 2 Each of these is preferably a group represented by the following formula (A-2). [ka] (In equation (A-2), R 4a , R 5a and R 6a Each of the following independently represents a hydrogen atom or an aliphatic hydrocarbon group with 1 to 3 carbon atoms, and X represents a divalent organic group. * represents a bond.

[0055] In equation (A-2), R 4a ~R 6a Each of these independently represents a hydrogen atom or an aliphatic hydrocarbon group having 1 to 3 carbon atoms. Examples of aliphatic hydrocarbon groups having 1 to 3 carbon atoms include alkyl groups having 1 to 3 carbon atoms. Examples of alkyl groups having 1 to 3 carbon atoms include methyl, ethyl, n-propyl, and 2-propyl groups, with methyl being preferred.

[0056] In formula (A-2), X represents a divalent organic group. The divalent organic group may contain an oxygen atom and a heteroatom such as a nitrogen atom. It is preferable that the heteroatom be present as a substituent. Examples of divalent organic groups include divalent aliphatic hydrocarbon groups which may have substituents, and divalent aromatic hydrocarbon groups which may have substituents. Among these, divalent aliphatic hydrocarbon groups which may have substituents are preferred as the divalent organic group.

[0057] The divalent aliphatic hydrocarbon group, which may have substituents, may be linear, branched, or cyclic. Furthermore, the divalent aliphatic hydrocarbon group may be saturated or unsaturated. The number of carbon atoms in the divalent aliphatic hydrocarbon group is preferably 1 to 10, more preferably 1 to 5. Examples of divalent aliphatic hydrocarbon groups include alkylene groups, alkenylene groups, and alkynylene groups.

[0058] Examples of alkylene groups include methylene, ethylene, propylene, butylene, pentylene, and hexylene groups.

[0059] Examples of alkenylene groups include etenylene, propenylene, butenylene, pentenylene, and hexenylene groups.

[0060] Examples of alkylylene groups include ethynylene groups and propynylene groups.

[0061] Among these, as optionally substituted divalent aliphatic hydrocarbon groups, alkylene groups having 1 to 10 carbon atoms are preferred, alkylene groups having 1 to 5 carbon atoms are more preferred, alkylene groups having 1 to 3 carbon atoms are even more preferred, and ethylene groups, propylene groups, or 2-hydroxypropylene groups are particularly preferred.

[0062] The number of carbon atoms in the optionally substituted divalent aromatic hydrocarbon group is preferably 6 to 20, more preferably 6 to 15. Examples of optionally substituted divalent aromatic hydrocarbon groups include arylene groups, such as 1,2-phenylene group, 1,3-phenylene group, 1,4-phenylene group, naphthylene group, anthracenylene group, biphenylene group, and 9,9-diphenyl-9H-fluorenylene group.

[0063] The divalent aliphatic hydrocarbon group and the divalent aromatic hydrocarbon group may have substituents. Examples of substituents are the same as those that may be present on the tetravalent organic group in A, and among these, a hydroxyl group is preferred. There may be one substituent or two or more substituents.

[0064] Examples of the groups in formula (A-2) include the groups (a5-1) to (a5-6) shown below. Among these, the group (a5-1), the group (a5-3), or the group (a5-4) is preferred for formula (A-2), with the group (a5-1) being more preferred. In the formula, * represents a bond. [ka]

[0065] Component (A) preferably has a structural unit represented by the following formula (A-3). [ka] (In formula (A-3), A 1a This represents a tetravalent organic group containing an aliphatic hydrocarbon group, B a represents a divalent organic group, R 1a and R 2a Each of these independently represents a monovalent organic group containing an ethylenically unsaturated bond.

[0066] In equation (A-3), A 1a This represents a tetravalent organic group containing an aliphatic hydrocarbon group. 1aThis is the same as the tetravalent organic group containing an aliphatic hydrocarbon group represented by A in formula (A-1).

[0067] In equation (A-3), B a represents a divalent organic group, which is the same as B in formula (A-1).

[0068] In equation (A-3), R 1a and R 2a Each of these independently represents a monovalent organic group containing an ethylenically unsaturated bond. Examples of monovalent organic groups containing an ethylenically unsaturated bond include vinyl groups, allyl groups, propagyl groups, ethynyl groups, phenylethynyl groups, butenyl groups, maleimide groups, nadiimide groups, (meth)acryloyl groups, and the group represented by formula (A-3a). 1a and R 2a Preferably, each of these can be independently represented by the following formula (A-3a). [ka] (In equation (A-3a), R 4b , R 5b and R 6b Each of these independently represents a hydrogen atom or an aliphatic hydrocarbon group having 1 to 3 carbon atoms; p a represents an integer between 0 and 10; * represents a combination.

[0069] In equation (A-3a), R 4b ~R 6b Each of these independently represents a hydrogen atom or an aliphatic hydrocarbon group having 1 to 3 carbon atoms, and R in formula (A-2) 4a ~R 6a It is the same as this.

[0070] In equation (A-2), p a The integer represents a number between 0 and 10, preferably between 0 and 5, more preferably between 0 and 3, and even more preferably 0.

[0071] Component (A) preferably has a structural unit represented by the following formula (A-4a) or the following formula (A-4b). [ka] (In equations (A-4a) and (A-4b), A 2a Each of these independently represents a tetravalent organic group, R 11 and R 12 Each of these independently represents a hydrogen atom or a monovalent organic group, and R 13 Each of the following independently represents a hydrogen atom or a methyl group; each of the following independently represents a single bond, a group represented by formula (a6-1), or a group represented by formula (a6-2); and each of the following independently represents a single bond, a group represented by formula (a6-3), or a group represented by formula (a6-4). m1 represents an integer from 1 to 5. [ka] (In equations (a6-1) to (a6-4), * represents a combination.)

[0072] In equations (A-4a) and (A-4b), A 2a Each of these independently represents a tetravalent organic group. 2a This is the same as A in equation (A-1).

[0073] In equations (A-4a) and (A-4b), R 11 and R 12 Each of these independently represents a hydrogen atom or a monovalent organic group. 11 and R 12 This is R in equation (A-1). 1 and R 2 It is the same as this.

[0074] In formulas (A-4a) and (A-4b), Xa independently represents a single bond, a group represented by formula (a6-1), or a group represented by formula (a6-2). Examples of the group represented by formula (a6-1) include the 1,2-phenylene group, the 1,3-phenylene group, and the 1,4-phenylene group. Examples of the group represented by formula (a6-2) include the groups (a6-2-1) to (a6-2-6) below. Among these, the group represented by formula (a6-1) is preferred for Xa, and the 1,4-phenylene group is more preferred. In the following formulas, * represents a bond. [ka]

[0075] In formulas (A-4a) and (A-4b), Xb independently represents a single bond, a group represented by formula (a6-3), or a group represented by formula (a6-4). Examples of groups represented by formula (a6-3) include the 1,2-phenylene group, the 1,3-phenylene group, and the 1,4-phenylene group. Examples of groups represented by formula (a6-4) include the following groups (a6-4-1) to (a6-4-3). Among these, a single bond is preferred for Xb. In the following formulas, * represents a bond. [ka]

[0076] In equations (A-4a) and (A-4b), R 13 Each of these independently represents either a hydrogen atom or a methyl group, and it is preferable that each represents a methyl group.

[0077] In equations (A-4a) and (A-4b), m1 independently represents an integer between 1 and 5, preferably an integer between 1 and 3, more preferably 2 or 3, and even more preferably 3.

[0078] Component (A) preferably has a structural unit represented by the following formula (A-5a) or formula (A-5b). [ka] (In equations (A-5a) and (A-5b), A 3a Each of these independently represents a tetravalent organic group containing an aliphatic hydrocarbon group, and R 1b and R 2b Each of these independently represents a monovalent organic group containing an ethylenically unsaturated bond, and R 13a Each of these independently represents a hydrogen atom or a methyl group, and Xa 1 Each of these independently represents a single bond, a group represented by formula (a7-1) below, or a group represented by formula (a7-2), and Xb 1 Each of these independently represents a single bond, a base represented by formula (a7-3), or a base represented by formula (a7-4). m2 represents an integer from 1 to 5. [ka] (In equations (a7-1) to (a7-4), * represents a bond.)

[0079] In equations (A-5a) and (A-5b), A 3a Each of these independently represents a tetravalent organic group. 3a This is the same as A in equation (A-1).

[0080] In equations (A-5a) and (A-5b), R 1a and R 1b Each of these independently represents a monovalent organic group containing an ethylenically unsaturated bond. 1a and R 1b This is R in equation (A-3). 1a and R 2a It is the same as this.

[0081] In equations (A-5a) and (A-5b), Xa 1 Each of these independently represents a single bond, a group represented by formula (a6-1), or a group represented by formula (a6-2). Xa 1 This is the same as Xa in equations (A-4a) and (A-4b).

[0082] In formula (A-5a) and formula (A-5b), Xb 1 each independently represents a single bond, a group represented by formula (a6-3), or a group represented by formula (a6-4). Xb 1 is the same as Xb in formula (A-4a) and formula (A-4b).

[0083] In formula (A-5a) and formula (A-5b), R 13a each independently represents a hydrogen atom or a methyl group, and preferably represents a methyl group.

[0084] In formula (A-5a) and formula (A-5b), m2 each independently represents an integer of 1 to 5, and m2 is the same as m1 in formula (A-4a) and formula (A-4b).

[0085] Component (A) preferably has a structural unit represented by the following formula (A-6a) or the following formula (A-6b).

Chemical formula

[0086] In formula (A-6a) and formula (A-6b), A 4a each independently represents a tetravalent organic group. A 4a is the same as A in formula (A-1).

[0087] In formula (A-6a) and formula (A-6b), R 1c and R 1c each independently represents a monovalent organic group containing an ethylenic unsaturated bond. R 1c and R 1c are the same as R 1a and R 2a in formula (A-3).

[0088] The polyimide precursor may be a copolymer containing structural units having an indane skeleton and structural units not containing an indane skeleton. For example, it may contain structural units containing an indane skeleton represented by formula (A-1) as well as structural units not containing an indane skeleton represented by formula (A-1). Furthermore, the polyimide precursor may be a copolymer having multiple structural units represented by different formulas (A-1).

[0089] The polyimide precursor may contain any structural units other than the amic acid structural units and amic acid ester structural units described above. Therefore, the polyimide precursor may be a copolymer containing the structural unit represented by formula (A-1) and any other structural units. In particular, the polyimide precursor preferably contains a large amount of amic acid structural units and amic acid ester structural units, and therefore, it is preferable that it contains a small amount of other structural units. For example, the mass of amic acid structural units and amic acid ester structural units is preferably 50% by mass or more, more preferably 70% by mass or more, and even more preferably 90% by mass or more, relative to 100% of the total mass of the polyimide precursor. The polyimide precursor may contain only the amic acid structural units and / or amic acid ester structural units described above as repeating units, and may not contain any other structural units. Furthermore, the amic acid structural units and / or amic acid ester structural units contained in the polyimide precursor may be one type or two or more types.

[0090] The structural unit represented by formula (A-1) is particularly preferably represented by any of the following formulas (a-1) to (a-31). Therefore, the polyimide precursor preferably contains one or more structural units selected from the group consisting of structural units represented by the following formulas (a-1) to (a-31), and more preferably contains either the structural unit represented by the following formula (a-6) or the structural unit represented by the following formula (a-26). [ka] [ka] [ka] [ka] [ka] [ka] [ka] [ka]

[0091] The number of repeating structural units represented by formula (A-1) is usually 2 or more, preferably 5 to 200, more preferably 5 to 150, even more preferably 5 to 100, and particularly preferably 5 to 70.

[0092] Specific examples of polyimide precursors having a structural unit represented by formula (A-1) include compounds containing the following repeating units (Aa-1) to (Aa-31). However, polyimide precursors having an amic acid ester structural unit represented by formula (A-1) are not limited to these specific examples. In the formula, n represents an integer from 5 to 200. [ka] [ka] [ka] [ka] [ka] [ka] [ka] [ka]

[0093] The polyimide precursor can transmit ultraviolet light with high transmittance. In one example, the total light transmittance at a wavelength of 365 nm of a 60 μm thick polyimide precursor layer is preferably 80% or more, more preferably 90% or more, and even more preferably 95% or more. The total light transmittance can be measured by the method described in Synthesis Example 1 of the Examples described later.

[0094] There are no particular limitations on the method for producing polyimide precursors. Polyimide precursors can be produced, for example, by reacting an aliphatic dianhydride with a diamine compound to obtain polyamic acid, and by reacting polyamic acid with an epoxy compound containing an ethylenically unsaturated bond. Examples of the aliphatic dianhydride, diamine compound, and epoxy compound containing an ethylenically unsaturated bond include those mentioned above. For methods of producing polyimide precursors, refer to the methods described in Japanese Patent Publication No. 3921734, Japanese Patent Publication No. 11-15152, Japanese Patent Publication No. 2015-209461, Japanese Patent Publication No. 2015-214680, Japanese Patent Publication No. 2017-219850, or Japanese Patent Publication No. 2018-146964.

[0095] As the polyimide, a resin containing a structure in which the above-mentioned polyimide precursor is cyclized to form an imide structure can be used. Furthermore, the polyimide may contain a radical-reactive group in its molecule. When a polyimide containing a radical-reactive group is used, the polyimide is crosslinked by exposure, which can effectively reduce the solubility of the first and second photosensitive resin compositions in the developer. Preferred polyimides include compounds containing the structure represented by the following formula (A-7). One type of polyimide may be used alone, or two or more types may be used in combination. [ka]

[0096] (In equation (A-7), A ai1 is the same as A in equation (A-1), and B ai1 is the same as B in equation (A-1), and n ai1 (This represents an integer between 5 and 200.)

[0097] Specific examples of polyimides include compounds containing the following repeating structures. However, polyimides are not limited to these specific examples. [ka]

[0098] (A) The weight-average molecular weight of component (A) is preferably 5,000 or more, more preferably 10,000 or more, even more preferably 30,000 or more, preferably 1,000,000 or less, more preferably 500,000 or less, and even more preferably 200,000 or less, from the viewpoint of critical resolution. The weight-average molecular weight of the resin can be measured as a polystyrene equivalent value by gel permeation chromatography (GPC).

[0099] The content of component (A) in the first photosensitive resin composition is preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, preferably 98% by mass or less, more preferably 97% by mass or less, and even more preferably 95% by mass or less, based on 100% by mass of the nonvolatile components of the first photosensitive resin composition, from the viewpoint of effectively forming holes in a thick photosensitive resin composition layer by exposure and development.

[0100] The content of component (A) in the second photosensitive resin composition is preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, preferably 98% by mass or less, more preferably 97% by mass or less, and even more preferably 95% by mass or less, based on 100% by mass of the nonvolatile components of the second photosensitive resin composition, from the viewpoint of effectively forming holes in a thick photosensitive resin composition layer by exposure and development.

[0101] The content of component (A) in the entire photosensitive resin composition layer is preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, preferably 98% by mass or less, more preferably 97% by mass or less, and even more preferably 95% by mass or less, based on 100% by mass of the nonvolatile components of the photosensitive resin composition layer, from the viewpoint of effectively forming holes in a thick photosensitive resin composition layer by exposure and development.

[0102] In this invention, unless otherwise specified, the content of each component in the first photosensitive resin composition is the value when the nonvolatile components in the first photosensitive resin composition are set to 100% by mass, and the nonvolatile components mean the entire nonvolatile components in the first photosensitive resin composition excluding the solvent. Unless otherwise specified, the content of each component in the second photosensitive resin composition is the value when the nonvolatile components in the second photosensitive resin composition are set to 100% by mass, and the nonvolatile components mean the entire nonvolatile components in the second photosensitive resin composition excluding the solvent. Furthermore, unless otherwise specified, the content of each component in the entire photosensitive resin composition layer is the value when the nonvolatile components in the photosensitive resin composition layer (the first and second photosensitive resin composition layers) are set to 100% by mass, and the nonvolatile components mean the entire nonvolatile components in the photosensitive resin composition layer excluding the solvent.

[0103] <(B) Photoradical Generator> The first and second photosensitive resin compositions each contain a photoradical generator (B) as component (B). Component (B) excludes any components corresponding to component (A). Component (B) generates radicals upon irradiation with active light, and these radicals can drive a crosslinking reaction. Component (B) may be used alone or in combination of two or more types.

[0104] Component (B) can generally be classified into (B-1) highly reactive photoradical generators and (B-2) photoradical generators with excellent deep curing properties. When laminating a photosensitive film onto a laminated member to produce a semiconductor package substrate, the second photosensitive resin composition layer is usually laminated so that it is bonded to the circuit board. Therefore, the second photosensitive resin composition layer is located at the bottom of the photosensitive resin composition layers during lamination. The total thickness of the photosensitive resin composition layers is usually quite thick, making it difficult for light to reach the bottommost second photosensitive resin composition layer. As a result, the shape of the vias created by exposure tends to be inversely tapered. The (B) components included in the first and second photosensitive resin compositions may include only component (B-1) or only component (B-2). However, from the viewpoint of improving undercut resistance and critical resolution, it is preferable to include both component (B-1) and component (B-2).

[0105] (B-1) Examples of highly reactive photoradical generators include photoradical generators containing an oxime ester structure. (B-1) Examples of components include oxime ester-based photoradical generators.

[0106] Examples of oxime ester-based photoradical generators include 2-(benzoyloxyimino)-1-[4-(phenylthio)phenyl]octan-1-one (OXE01), [1-[9-ethyl-6-(2-methylbenzoyl)carbazole-3-yl]ethylideneamino]acetate (OXE02), etanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-,1-(O-acetyloxime), and others.

[0107] (B-1) A highly reactive photoradical generator may be a commercially available product. Specific examples of commercially available highly reactive photoradical generators include BASF's "Irgacure TPO," "Irgacure OXE-01," and "Irgacure OXE-02," and ADEKA's "N-1919."

[0108] In the present invention, (B-2) the photoradical generator with excellent deep curing properties has an absorption maximum in the wavelength range of 340 nm to 420 nm, or an extinction coefficient at 365 nm of 4000 ml / gcm or less. Examples of (B-2) components include acylphosphine-based photoradical generators, aminoketone-based photoradical generators, α-hydroxyketone-based photoradical generators, benzoin-based photoradical generators, benzylketal-based photoradical generators, and the like.

[0109] Examples of acylphosphine-based photoradical generators include bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, (2,4,6-trimethylbenzoyl)diphenylphosphine oxide, and polyoxyethylene glycerin ether tris[phenyl(2,4,6-trimethylbenzoyl)phosphine] (Polymeric TPO-L).

[0110] Examples of α-aminoketone-based photoradical generators include 2-methyl-1-phenyl-2-morpholinopropan-1-one, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2-methyl-1-(4-hexylphenyl)-2-morpholinopropan-1-one, 2-ethyl-2-(dimethylamino)-1-(4-morpholinophenyl)butan-1-one, 2-benzyl-2-(dimethylamino)-1-(4-morpholinophenyl)butan-1-one, 2-(dimethylamino)-2-(4-methylphenylmethyl)-1-(4-morpholinophenyl)butan-1-one, and 2-methyl-1-(9,9-dibutylfluoren-2-yl)-2-morpholinopropan-1-one.

[0111] Examples of α-hydroxyketone-based photoradical generators include 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenylpropanone, 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methylpropanone, and 2-hydroxy-1-{4-[4-(2-hydroxy-2-methylpropionyl)benzyl]phenyl}-2-methylpropan-1-one.

[0112] Examples of benzoin-based photoradical generators include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzoin isobutyl ether.

[0113] Examples of benzyl ketal-based photoradical generators include 2,2-dimethoxy-2-phenylacetophenone.

[0114] (B-2) A commercially available photoradical generator with excellent deep curing properties may be used. Specific examples of commercially available photoradical generators with excellent deep curing properties include IGM's "Omnirad907," "Omnirad369," "Omnirad379," "Omnirad379EG," "Omnirad819," and "OmniradTPO."

[0115] From the viewpoint of improving undercut resistance and critical resolution, the content of component (B) in the first photosensitive resin composition is preferably 0.03 parts by mass or more, more preferably 0.1 parts by mass or more, even more preferably 0.5 parts by mass or more, preferably 5 parts by mass or less, more preferably 4 parts by mass or less, and even more preferably 3 parts by mass or less, based on 100 parts by mass of component (A) in the first photosensitive resin composition.

[0116] From the viewpoint of improving undercut resistance and critical resolution, the content of component (B-1) in the first photosensitive resin composition is preferably 0.1 parts by mass or more, more preferably 0.2 parts by mass or more, even more preferably 0.3 parts by mass or more, preferably 2 parts by mass or less, more preferably 1.5 parts by mass or less, and even more preferably 1 part by mass or less, based on 100 parts by mass of component (A) in the first photosensitive resin composition.

[0117] From the viewpoint of improving undercut resistance and critical resolution, the content of component (B-2) in the first photosensitive resin composition is preferably 0.03 parts by mass or more, more preferably 0.05 parts by mass or more, even more preferably 0.1 parts by mass or more, preferably 1 part by mass or less, more preferably 0.8 parts by mass or less, and even more preferably 0.5 parts by mass or less, per 100 parts by mass of component (A) in the first photosensitive resin composition.

[0118] As for the content of component (B) in the first photosensitive resin composition, from the viewpoint of improving undercut resistance and critical resolution, when the nonvolatile components of the first photosensitive resin composition are taken as 100% by mass, it is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, even more preferably 0.5% by mass or more, preferably 5% by mass or less, more preferably 4% by mass or less, and even more preferably 3% by mass or less.

[0119] From the viewpoint of improving undercut resistance and critical resolution, the content of component (B-1) in the first photosensitive resin composition is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, even more preferably 0.5% by mass or more, preferably 5% by mass or less, more preferably 4% by mass or less, and even more preferably 3% by mass or less, when the nonvolatile components of the first photosensitive resin composition are taken as 100% by mass.

[0120] When the content of component (B-2) in the first photosensitive resin composition is considered from the perspective of improving undercut resistance and ultimate resolution, when the non-volatile components of the first photosensitive resin composition are taken as 100% by mass, it is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, still more preferably 0.5% by mass or more, and preferably 5% by mass or less, more preferably 4% by mass or less, still more preferably 3% by mass or less.

[0121] Let the content of component (B-1) in the first photosensitive resin composition be b when the non-volatile components of the first photosensitive resin composition are taken as 100% by mass 1-1 and let the content of component (B-2) in the first photosensitive resin composition be b 2-1 When this is the case, b 1-1 / b 1-2 is preferably 0.5 or more, more preferably 1 or more, still more preferably 1.5 or more, 2 or more, and preferably 15 or less, more preferably 12 or less, still more preferably 10 or less. By adjusting the amounts of components (B-1) and (B-2) in the first photosensitive resin composition so that the quantitative ratio of components (B-1) and (B-2) contained in the first photosensitive resin composition falls within such a range, a cured product excellent in undercut resistance can be obtained.

[0122] When the content of component (B) in the second photosensitive resin composition is considered from the perspective of improving undercut resistance and ultimate resolution, based on 100 parts by mass of component (A) in the second photosensitive resin composition, it is preferably 0.05 part by mass or more, more preferably 0.1 part by mass or more, still more preferably 0.5 part by mass or more, and preferably 8 parts by mass or less, more preferably 5 parts by mass or less, still more preferably 4 parts by mass or less.

[0123] When the content of component (B-1) in the second photosensitive resin composition is considered from the perspective of improving undercut resistance and ultimate resolution, based on 100 parts by mass of component (A) in the second photosensitive resin composition, it is preferably 0.1 part by mass or more, more preferably 0.3 part by mass or more, still more preferably 0.5 part by mass or more, and preferably 5 parts by mass or less, more preferably 4 parts by mass or less, still more preferably 3 parts by mass or less.

[0124] From the viewpoint of improving undercut resistance and critical resolution, the content of component (B-2) in the second photosensitive resin composition is preferably 0.03 parts by mass or more, more preferably 0.05 parts by mass or more, even more preferably 0.1 parts by mass or more, preferably 1 part by mass or less, more preferably 0.8 parts by mass or less, and even more preferably 0.5 parts by mass or less, per 100 parts by mass of component (A) in the second photosensitive resin composition.

[0125] As for the content of component (B) in the second photosensitive resin composition, from the viewpoint of improving undercut resistance and critical resolution, when the nonvolatile components of the second photosensitive resin composition are taken as 100% by mass, it is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, even more preferably 0.5% by mass or more, preferably 5% by mass or less, more preferably 4% by mass or less, and even more preferably 3% by mass or less.

[0126] When the nonvolatile components of the first photosensitive resin composition are set to 100% by mass, the content of component (B) in the first photosensitive resin composition is b. 1-0 The content of component (B) in the second photosensitive resin composition is set to b 2-0 When this is the case, b 1-0 / b 2-0 However, it is preferably 0.1 or more, more preferably 0.3 or more, even more preferably 0.5 or more, 0.6 or more, preferably 3 or less, more preferably 2 or less, even more preferably 1.5 or less, 1 or less, 0.9 or less. By adjusting the amount of component (B) in the first and second photosensitive resin compositions to fall within this range, a cured product with excellent undercut resistance can be obtained.

[0127] From the viewpoint of improving undercut resistance and critical resolution, the content of component (B-1) in the second photosensitive resin composition is preferably 0.05% by mass or more, more preferably 0.1% by mass or more, even more preferably 0.5% by mass or more, preferably 5% by mass or less, more preferably 4% by mass or less, and even more preferably 3% by mass or less, when the nonvolatile components of the second photosensitive resin composition are taken as 100% by mass.

[0128] From the viewpoint of improving undercut resistance and critical resolution, the content of component (B-2) in the second photosensitive resin composition is preferably 0.05% by mass or more, more preferably 0.03% by mass or more, even more preferably 0.1% by mass or more, preferably 1.5% by mass or less, more preferably 1% by mass or less, and even more preferably 0.5% by mass or less, when the nonvolatile components of the second photosensitive resin composition are taken as 100% by mass.

[0129] When the nonvolatile component of the second photosensitive resin composition is set to 100% by mass, the content of component (B-1) in the second photosensitive resin composition is b 2-1 The content of component (B-2) in the second photosensitive resin composition is set to b 2-2 When this is the case, b 2-1 / b 2-2 However, it is preferably 1 or more, more preferably 2 or more, even more preferably 2.5 or more, 3 or more, preferably 20 or less, more preferably 15 or less, even more preferably 13 or less, 10 or less. By adjusting the amounts of component (B-1) and component (B-2) contained in the second photosensitive resin composition to be within such a range, a cured product with excellent undercut resistance can be obtained.

[0130] When the nonvolatile components of the first photosensitive resin composition are set to 100% by mass, the content of component (B-1) in the first photosensitive resin composition is b 1-1 The content of component (B-1) in the second photosensitive resin composition is set to b 2-1 When this is the case, b 1-1 / b 2-1 However, it is preferably 0.1 or more, more preferably 0.3 or more, even more preferably 0.5 or more, preferably 3 or less, more preferably 1.5 or less, and even more preferably 1 or less. By adjusting the amount ratio of component (B-1) contained in the first and second photosensitive resin compositions to be within this range, the difference in absorbance between the first and second photosensitive resin composition layers can be easily adjusted to a predetermined range, and a cured product with excellent undercut resistance can be obtained.

[0131] When the nonvolatile components of the first photosensitive resin composition are set to 100% by mass, the content of component (B-2) in the first photosensitive resin composition is b 1-2 The content of component (B-2) in the second photosensitive resin composition is set to b 2-2 When this is the case, b 1-2 / b 2-2 However, it is preferably 0.1 or more, more preferably 0.5 or more, even more preferably 0.8 or more, preferably 3 or less, more preferably 1.5 or less, and even more preferably 1.3 or less. By adjusting the amount ratio of component (B-2) contained in the first and second photosensitive resin compositions to be within this range, the difference in absorbance between the first and second photosensitive resin composition layers can be easily adjusted to a predetermined range, and a cured product with excellent undercut resistance can be obtained.

[0132] As for the content of component (B) in the photosensitive resin composition layer, from the viewpoint of improving undercut resistance and critical resolution, it is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, even more preferably 0.5% by mass or more, preferably 5% by mass or less, more preferably 4% by mass or less, and even more preferably 3% by mass or less, when the nonvolatile component of the photosensitive resin composition layer is taken as 100% by mass.

[0133] From the viewpoint of improving undercut resistance and critical resolution, the content of component (B) in the photosensitive resin composition layer is preferably 0.05 parts by mass or more, more preferably 0.1 parts by mass or more, even more preferably 0.5 parts by mass or more, preferably 8 parts by mass or less, more preferably 5 parts by mass or less, and even more preferably 3 parts by mass or less, per 100 parts by mass of component (A) in the photosensitive resin composition layer.

[0134] From the viewpoint of improving undercut resistance and critical resolution, the content of component (B-1) in the photosensitive resin composition layer is preferably 0.03 parts by mass or more, more preferably 0.1 parts by mass or more, even more preferably 0.5 parts by mass or more, preferably 5 parts by mass or less, more preferably 4 parts by mass or less, and even more preferably 3 parts by mass or less, per 100 parts by mass of component (A) in the photosensitive resin composition layer.

[0135] From the viewpoint of improving undercut resistance and critical resolution, the content of component (B-2) in the photosensitive resin composition layer is preferably 0.03 parts by mass or more, more preferably 0.05 parts by mass or more, even more preferably 0.1 parts by mass or more, preferably 3 parts by mass or less, more preferably 1 part by mass or less, and even more preferably 0.5 parts by mass or less, per 100 parts by mass of component (A) in the photosensitive resin composition layer.

[0136] From the viewpoint of improving undercut resistance, the content of component (B) in the first photosensitive resin composition is preferably less than the content of component (B) in the second photosensitive resin composition. Specifically, when the content of component (B) in the first photosensitive resin composition per 100 parts by mass of component (A) is b1, and the content of component (B) in the second photosensitive resin composition per 100 parts by mass of component (A) is b2, then b2-b1 is preferably 0.1 or more, more preferably 0.15 or more, even more preferably 0.2 or more, preferably 2 or less, more preferably 1.5 or less, and even more preferably 1 or less.

[0137] -(C) Photocrosslinking agent- The first and second photosensitive resin compositions each contain (C) a photocrosslinking agent as component (C). This (B) crosslinking agent does not include components (A) and (B). When the first and second photosensitive resin compositions are irradiated with active light, radicals are generated from the (B) photoradical generator, causing a crosslinking reaction of the (C) photocrosslinking agent, which effectively reduces their solubility in the developer. Therefore, the difference in solubility in the developer between the exposed and unexposed areas of the first and second photosensitive resin compositions can be effectively increased. Consequently, during development, it becomes possible to selectively remove the first and second photosensitive resin compositions in areas other than those where the crosslinking reaction has progressed, thereby advantageously forming a negative-type pattern. As a result, it becomes possible to ensure film thickness and resolution after development. The (C) photocrosslinking agent may be used alone or in combination of two or more types.

[0138] (C) As a photocrosslinking agent, a compound capable of carrying out a crosslinking reaction upon exposure may be used. (C) Since the photocrosslinking agent contains an ethylenically unsaturated bond, this ethylenically unsaturated bond can usually undergo a crosslinking reaction. (C) As a photocrosslinking agent, a compound containing an ethylenically unsaturated bond, wherein at least one of the carbon atoms at the α position of the ethylenically unsaturated bond is bonded to a carbonyl group or an aromatic group, is more preferable. The carbon atom at the α position of the ethylenically unsaturated bond refers to the first carbon atom adjacent to the carbon atom bonded by the carbon-carbon unsaturated bond.

[0139] (C) Photocrosslinking agents generally contain groups containing ethylenically unsaturated bonds. Hereinafter, "groups containing ethylenically unsaturated bonds" may be referred to as "ethylenically unsaturated groups." Ethylenelycol groups are usually monovalent groups, and examples include vinyl groups, allyl groups, propagyl groups, butenyl groups, ethynyl groups, phenylethynyl groups, maleimide groups, nadiimide groups, and (meth)acryloyl groups. From the viewpoint of reactivity in photoradical polymerization, (meth)acryloyl groups and phenylethynyl groups are preferred, and (meth)acryloyl groups are particularly preferred. (B) Since crosslinking agents contain ethylenically unsaturated bonds, photoradical polymerization is possible, but for photoradical polymerization under general conditions, compounds having a carbonyl group or an aromatic group at least one of the α positions of the ethylenically unsaturated bond are preferred.

[0140] (C) The number of ethylenically unsaturated bonds per molecule of the photocrosslinking agent is usually one or more. From the viewpoint of critical resolution, the number of ethylenically unsaturated bonds per molecule of the photocrosslinking agent is preferably two or more, and more preferably three or more. There is no particular upper limit, but it may be 20 or less. If the photocrosslinking agent contains two or more ethylenically unsaturated groups per molecule, these ethylenically unsaturated groups may be the same or different.

[0141] (C) As a photocrosslinking agent, a compound represented by the following formula (C-1) is preferred. [ka] In the formula, R1c Each independently represents a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms, and each independently represents a linear or branched alkylene group having 1 to 20 carbon atoms which may contain an oxygen atom, an arylene group which may contain an oxygen atom, or a linear or branched alkenylene group having 2 to 20 carbon atoms which may contain an oxygen atom, and A 1c This represents a linear, cyclic, or branched organic group with 1 to 10 carbon atoms and an nc valency. nc is a positive integer between 2 and 20.

[0142] R 1c Each of these independently represents a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms. Examples of linear or branched alkyl groups having 1 to 4 carbon atoms include methyl, ethyl, propyl, isopropyl, 1-butyl, s-butyl, and t-butyl groups. Among these, R 1c Hydrogen atoms and methyl groups are preferred as these elements.

[0143] Z independently represents a linear or branched alkylene group having 1 to 20 carbon atoms, which may contain an oxygen atom; an arylene group having an oxygen atom; or a linear or branched alkenylene group having 2 to 20 carbon atoms, which may contain an oxygen atom. Among the linear or branched alkylene groups having 1 to 20 carbon atoms, linear or branched alkylene groups having 1 to 10 carbon atoms are preferred, and linear or branched alkylene groups having 1 to 6 carbon atoms are more preferred. Examples of such alkylene groups include methylene, ethylene, propylene, butylene, pentylene, and hexylene groups, with methylene being preferred. Furthermore, the alkylene group may also be an oxyalkylene group containing an oxygen atom; specific examples of such groups are shown below. In the formula, "*" represents a combination, c1 represents an integer from 1 to 20, c2 represents an integer from 1 to 10, c3 represents an integer from 1 to 19, and c4 represents an integer from 1 to 9. [ka]

[0144] As for arylene groups that may contain an oxygen atom, arylene groups having 6 to 20 carbon atoms are preferred, arylene groups having 6 to 15 carbon atoms are more preferred, and arylene groups having 6 to 10 carbon atoms are even more preferred. Examples of such arylene groups include phenylene groups and naphthylene groups. Furthermore, arylene groups may contain an oxygen atom, and specific examples of such groups include those shown below. In the formula, "*" represents a bond, and c5 represents an integer from 1 to 3. [ka]

[0145] As a linear or branched alkenylene group having 2 to 20 carbon atoms, which may contain an oxygen atom, a linear or branched alkenylene group having 2 to 10 carbon atoms is preferred, and a linear or branched alkenylene group having 2 to 6 carbon atoms is more preferred. Examples of such alkenylene groups include etenylene, propenylene, butenylene, pentenylene, and hexenylene. The alkenylene group may also be an oxyalkenylene group containing an oxygen atom, and specific examples of such groups include those shown below. In the formula, "*" represents a bond, and c6 represents an integer from 1 to 10. A propenylene group is preferred as the alkenylene group. [ka]

[0146] In particular, Z is preferably a linear or branched alkylene group having 1 to 20 carbon atoms, which may contain an oxygen atom, and oxyalkylene groups and methylene groups are more preferred.

[0147] A 1cThis represents a linear, cyclic, or branched organic group with 1 to 10 carbon atoms and an nc valency. Examples of nc valency organic groups include nc valency hydrocarbon groups that may contain an oxygen atom, nc valency groups derived from bisphenol, nc valency groups derived from fluorene, nc valency groups derived from tricyclodecane, or nc valency groups derived from isocyanuric groups. Examples of nc valency hydrocarbon groups that may contain an oxygen atom include nc valency aliphatic hydrocarbon groups that may contain an oxygen atom and nc valency aromatic hydrocarbon groups that may contain an oxygen atom. An nc valency aliphatic hydrocarbon group that may contain an oxygen atom is preferred, and for example, when nc is 2, an alkylene group is preferred. 1c Specific examples of the base represented by include the following. In the formula, "*" represents a bond. [ka]

[0148] nc represents a positive integer between 2 and 20, preferably between 2 and 8, more preferably between 2 and 6, even more preferably between 2 and 5, and even more preferably between 3 or 4, or 2 or 3.

[0149] (C) The photocrosslinking agent may be a compound represented by the following formula (C-2). [ka] In formula (C-2), R 2c Each of these independently represents either a hydrogen atom or a methyl group.

[0150] R 2c Each of these independently represents either a hydrogen atom or a methyl group, with the methyl group being preferred.

[0151] (C)Specific examples of photocrosslinking agents include dipentaerythritol hexaacrylate, dipentaerythritol tetraacrylate, and the following compounds (CL-1) to (CL-11). However, the components of (C) are not limited to these. [ka] [ka]

[0152] (C) Commercially available photocrosslinking agents may be used. Examples of commercially available products include NK ester-D-TMP, 4G, 9G, 14G, 23G, DCP, TMPT, and A-TMPT from Shin Nakamura Chemical Co., Ltd.; SR209 from Tomoe Engineering Co., Ltd.; M-940 and M-933 from Toagosei Co., Ltd.; DPHA (dipentaerythritol hexaacrylate) from Nippon Kayaku Co., Ltd.; and CN2301 and CN2304 from Sartomer Japan Co., Ltd.

[0153] From the viewpoint of improving undercut resistance and critical resolution, the content of component (C) in the first photosensitive resin composition is preferably 2 parts by mass or more, more preferably 4 parts by mass or more, even more preferably 5 parts by mass or more, preferably 15 parts by mass or less, more preferably 10 parts by mass or less, and even more preferably 8 parts by mass or less, per 100 parts by mass of component (A) in the first photosensitive resin composition.

[0154] The content of component (C) in the first photosensitive resin composition is preferably 1% by mass or more, more preferably 2% by mass or more, even more preferably 3% by mass or more, preferably 15% by mass or less, more preferably 10% by mass or less, and even more preferably 8% by mass or less, based on 100% by mass of the nonvolatile components of the first photosensitive resin composition.

[0155] From the viewpoint of improving undercut resistance and critical resolution, the content of component (C) in the second photosensitive resin composition is preferably 2 parts by mass or more, more preferably 4 parts by mass or more, even more preferably 5 parts by mass or more, preferably 15 parts by mass or less, more preferably 10 parts by mass or less, and even more preferably 8 parts by mass or less, per 100 parts by mass of component (A) in the second photosensitive resin composition.

[0156] The content of component (C) in the second photosensitive resin composition is preferably 1% by mass or more, more preferably 2% by mass or more, still more preferably 3% by mass or more, and preferably 15% by mass or less, more preferably 10% by mass or less, still more preferably 8% by mass or less, based on 100% by mass of the non-volatile components of the second photosensitive resin composition, from the viewpoint of improving undercut resistance and ultimate resolution.

[0157] The content of component (C) in the photosensitive resin composition layer is preferably 1% by mass or more, more preferably 2% by mass or more, still more preferably 3% by mass or more, and preferably 15% by mass or less, more preferably 10% by mass or less, still more preferably 8% by mass or less, when the non-volatile components of the photosensitive resin composition layer are taken as 100% by mass, from the viewpoint of improving undercut resistance and ultimate resolution.

[0158] The content of component (C) in the photosensitive resin composition layer is preferably 2 parts by mass or more, more preferably 4 parts by mass or more, still more preferably 5 parts by mass or more, and preferably 15 parts by mass or less, more preferably 10 parts by mass or less, still more preferably 8 parts by mass or less, with respect to 100 parts by mass of component (A) in the photosensitive resin composition layer, from the viewpoint of improving undercut resistance and ultimate resolution.

[0159] -(D) Optional additive- The first and second photosensitive resin compositions may contain, as optional components, (D) an optional additive in addition to the above-described components (A) to (C). The (D) optional additive as component (D) may be used alone or in combination of two or more.

[0160] (D) Optional additives include, for example, sensitizers; photopolymerization initiators; adhesion aids; surfactants such as fluorinated surfactants, nonionic surfactants, cationic surfactants, anionic surfactants, and silicone surfactants; thermoplastic resins; colorants such as phthalocyanine blue, phthalocyanine green, iodine green, diazo yellow, crystal violet, titanium dioxide, carbon black, and naphthalene black; polymerization inhibitors such as hydroquinone, phenothiazine, methylhydroquinone, hydroquinone monomethyl ether, catechol, and pyrogallol; thickeners such as bentonite and montmorillonite; silicone, fluorinated, and vinyl resin-based defoamers; flame retardants such as epoxy resins, antimony compounds, phosphorus compounds, aromatic condensed phosphate esters, and halogenated condensed phosphate esters; and thermosetting resins such as phenolic resins and cyanate ester resins.

[0161] -(E) Solvent- The first and second photosensitive resin compositions may contain, in combination with the non-volatile components such as components (A) to (D) described above, an optional component, a solvent (E). The solvent (E) is preferably a volatile component capable of uniformly dissolving at least one of components (A) to (D).

[0162] (E) Examples of solvents include ether compound solvents having 2 to 9 carbon atoms, such as dimethyl ether, diethyl ether, methyl ethyl ether, tetrahydrofuran, dioxane, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, and triethylene glycol dimethyl ether; ketone compound solvents having 2 to 6 carbon atoms, such as acetone and methyl ethyl ketone; saturated hydrocarbon compound solvents having 5 to 10 carbon atoms, such as n-pentane, cyclopentane, n-hexane, cyclohexane, methylcyclohexane, and decalin; benzene, toluene Examples include aromatic hydrocarbon solvents having 6 to 10 carbon atoms, such as xylene, mesitylene, and tetralin; ester solvents having 3 to 9 carbon atoms, such as methyl acetate, ethyl acetate, γ-butyrolactone, and methyl benzoate; halogen-containing solvents having 1 to 10 carbon atoms, such as chloroform, methylene chloride, and 1,2-dichloroethane; nitrogen-containing solvents having 2 to 10 carbon atoms, such as acetonitrile, N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone; and sulfur-containing solvents such as dimethyl sulfoxide.

[0163] Furthermore, examples of solvents (E) include N-ethyl-2-pyrrolidone, tetrahydrofuran, N,N-dimethylacetamide, dimethyl sulfoxide, hexamethylphosphoramide, pyridine, cyclopentanone, α-acetyl-γ-butyrolactone, tetramethylurea, 1,3-dimethyl-2-imidazolinone, N-cyclohexyl-2-pyrrolidone, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, methyl ethyl ketone, methyl isobutyl ketone, anisole, ethyl acetate, ethyl lactate, and butyl lactate.

[0164] (E) The solvent may be used alone or in combination of two or more types.

[0165] The amount of solvent (E) in the first photosensitive resin composition is preferably 1% by mass or more, more preferably 2% by mass or more, even more preferably 3% by mass or more, preferably 40% by mass or less, more preferably 35% by mass or less, and even more preferably 30% by mass or less, when the entire first photosensitive resin composition including solvent (E) is considered to be 100% by mass.

[0166] The amount of solvent (E) in the second photosensitive resin composition is preferably 1% by mass or more, more preferably 2% by mass or more, even more preferably 3% by mass or more, preferably 40% by mass or less, more preferably 35% by mass or less, and even more preferably 30% by mass or less, when the entire second photosensitive resin composition including solvent (E) is considered to be 100% by mass.

[0167] <Other layers> The photosensitive film may include other layers as needed. Such other layers include a photosensitive resin composition layer different from the first and second photosensitive resin composition layers, provided between the first and second photosensitive resin composition layers. This photosensitive resin composition layer may be formed of multiple layers. The photosensitive resin composition layer different from the first and second photosensitive resin composition layers may contain any of components (A) to (E). Even if the photosensitive film has a photosensitive resin composition layer different from the first and second photosensitive resin composition layers, the difference between the absorbance of the first photosensitive resin composition layer adjacent to the support and the absorbance of the second photosensitive resin composition layer, which is the outermost layer of the photosensitive resin composition layers, should be 0.05 or more and 0.5 or less. Furthermore, it is preferable that the total thickness of these photosensitive resin composition layers is within the range of the thickness of the photosensitive resin composition layers.

[0168] Furthermore, the photosensitive film may also have other layers, such as a protective film provided on the side of the second photosensitive resin composition layer that is not bonded to the first photosensitive resin composition layer (i.e., the side opposite to the first photosensitive resin composition layer). By laminating the protective film, it is possible to suppress the adhesion of dust and other debris and scratches to the surface of the second photosensitive resin composition layer.

[0169] As the protective film, for example, a film formed from the same material as the support described above can be used. The thickness of the protective film is not particularly limited, but is preferably in the range of 1 μm to 40 μm, more preferably in the range of 5 μm to 30 μm, and even more preferably in the range of 10 μm to 30 μm.

[0170] <Method for manufacturing photosensitive film> As described above, the photosensitive film of the present invention comprises a support, a first photosensitive resin composition layer, and a second photosensitive resin composition layer in that order, and optionally includes a protective film or the like. The method for manufacturing such a photosensitive film is: (1) A step of applying a first resin varnish, which is a solution of the first photosensitive resin composition, to a support, drying it, and forming a first resin sheet having a layer of the first photosensitive resin composition on the support. (2) A step of applying a second resin varnish, which is a solution of the second photosensitive resin composition, onto a protective film, drying it, and forming a second resin sheet having a layer of the second photosensitive resin composition on the protective film, and (3) The process includes laminating the first resin sheet and the second resin sheet such that the first photosensitive resin composition layer and the second photosensitive resin composition layer are bonded together.

[0171] -Process (1)- In step (1), a first resin varnish is prepared by dissolving the first photosensitive resin composition in a solvent, this first resin varnish is applied to a support, and then dried to form a layer of the first photosensitive resin composition. The solvent is as described above.

[0172] Examples of the first resin varnish application methods include gravure coating, microgravure coating, reverse coating, kiss reverse coating, die coating, slot die coating, lip coating, comma coating, blade coating, roll coating, knife coating, curtain coating, chamber gravure coating, slot orifice coating, spin coating, slit coating, spray coating, dip coating, hot melt coating, bar coating, applicator coating, air knife coating, curtain flow coating, offset printing, brush coating, and full-surface printing by screen printing. Among these, the spin coating method is preferred as the resin varnish application method.

[0173] The first resin varnish may be applied in several coats, in a single coat, or by combining several different methods. Among these, the die-coating method is preferred because it offers excellent uniformity. Furthermore, to avoid contamination with foreign matter, it is preferable to carry out the coating process in an environment with minimal foreign matter generation, such as a clean room.

[0174] Drying may be carried out by known methods such as heating or blowing hot air. The drying conditions are not particularly limited, but the drying should be carried out so that the solvent content in the first photosensitive resin composition layer is 10% by mass or less, preferably 5% by mass or less. Depending on the boiling point of the solvent in the first resin varnish, for example, when using a first resin varnish containing 30% by mass to 60% by mass of solvent, the first photosensitive resin composition layer can be formed by drying at 50°C to 150°C for 3 to 10 minutes.

[0175] -Process (2)- In step (2), a second resin varnish is prepared by dissolving the second photosensitive resin composition in a solvent, and this second resin varnish is applied to the protective film and further dried to form a second photosensitive resin composition layer. The solvent is as described above. Step (2) can be carried out in the same manner as in step (1).

[0176] -Process (3)- In Process (3), the first resin sheet and the second resin sheet are laminated so that the first photosensitive resin composition layer and the second photosensitive resin composition layer are joined. As a result, a photosensitive film is formed in the order of a support, the first photosensitive resin composition layer, the second photosensitive resin composition layer, and a protective film. When laminating the photosensitive film on a member to be laminated, it can be used by peeling off the protective film.

[0177] The lamination may be carried out by a vacuum lamination method. In the vacuum lamination method, the lamination temperature is preferably in the range of 60°C to 160°C, more preferably in the range of 80°C to 140°C, the lamination pressure is preferably in the range of 0.098 MPa to 1.77 MPa, more preferably in the range of 0.29 MPa to 1.47 MPa, and the lamination time is preferably in the range of 20 seconds to 400 seconds, more preferably in the range of 30 seconds to 300 seconds. The lamination is preferably carried out under a reduced pressure condition of a pressure of 26.7 hPa or less.

[0178] The lamination can be carried out by a commercially available vacuum laminator. Examples of commercially available vacuum laminators include a vacuum pressure type laminator manufactured by Meiki Seisakusho Co., Ltd., a vacuum applicator manufactured by Nichio Materials Co., Ltd., a batch type vacuum pressure laminator, and the like.

[0179] As a method for manufacturing the photosensitive film, in addition to the above-described manufacturing method, for example, a second varnish may be applied and dried on the first photosensitive resin composition layer formed on a support to form a second photosensitive resin composition layer on the first photosensitive resin composition layer. The application and drying are as described above.

[0180] <Properties, etc. of the photosensitive film> The photosensitive resin composition layer of the photosensitive film of the present invention exhibits excellent undercut resistance even with a thick film thickness. A photosensitive resin composition layer is fabricated on a silicon wafer. A mask is used to draw circular holes (via holes) with exposure pattern aperture diameters of 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, and 70 μm on the photosensitive resin composition layer, and the exposure amount is 200 mJ / cm². 2 300 mJ / cm² 2 , 400 mJ / cm 2 , and 500 mJ / cm 2 Each setting is adjusted, and development is performed to form each round hole. Then, the undercut of the limit opening via (the difference between the radius of the bottom and the radius of the top (radius of the bottom - radius of the top)) is determined. At this time, the undercut can preferably be 4 μm or less, more preferably less than 2 μm, and especially preferably eliminated. The undercut resistance can be evaluated according to the method described in the examples below.

[0181] The photosensitive resin composition layer of the photosensitive film of the present invention typically exhibits excellent critical resolution even with a thick film thickness. Therefore, by using the photosensitive film of the present invention, small-diameter holes can be formed by exposure and development. The degree of critical resolution can be evaluated by the aspect ratio between the aperture diameter of the critical aperture via and the film thickness of the photosensitive resin composition layer. For example, a photosensitive resin composition layer is fabricated on a silicon wafer. A mask is used to draw circular holes (via holes) with exposure patterns of aperture diameters of 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, and 70 μm on the photosensitive resin composition layer, and the exposure amount is 200 mJ / cm². 2 300 mJ / cm² 2 , 400 mJ / cm 2 , and 500 mJ / cm 2Each setting is adjusted, and development is performed to form each circular hole. Then, the diameter of the bottom of the circular hole is observed to identify the smallest circular hole (limit aperture via) that can be opened without residue or peeling. The aspect ratio of the diameter of the limit aperture via (film thickness (μm) / via diameter (μm)) is preferably 0.5 or higher, more preferably 0.7 or higher, more preferably 0.8 or higher, even more preferably 0.9 or higher, and particularly preferably 1.0 or higher. There is no particular upper limit, but it is preferably 1.5 or lower. The limit resolution can be evaluated according to the method described in the examples below.

[0182] The cured product of the photosensitive resin composition layer of the photosensitive film of the present invention typically exhibits excellent adhesion to metals such as copper foil. For example, a photosensitive resin composition layer is fabricated on a silicon wafer on which copper foil is laminated. A mask is used to draw circular holes with an aperture diameter of 70 μm in the exposure pattern on the photosensitive resin composition layer, and the exposure dose is 200 mJ / cm². 2 The material is exposed and developed to form a circular hole, and the cross-section of this circular hole is observed. The presence or absence of peeling between the bottom (via bottom) of the circular hole and the copper foil, and the length of the peeling are measured. At that time, the length of the peeling is preferably 4 μm or less, more preferably 2 μm or less, even more preferably less than 2 μm, and particularly preferably no peeling at all. Adhesion can be measured by the method described in the examples below.

[0183] The applications of the photosensitive film of the present invention are not particularly limited. For example, since the photosensitive film has a photosensitive resin composition layer, it is useful as a PID (Photo Imaginable Dielectric). Furthermore, the photosensitive film can be used in a wide range of applications where a photosensitive resin composition layer is used, such as insulating resin sheets (prepregs, etc.), silicon wafers, circuit boards (laminated board applications, multilayer printed wiring board applications, etc.), solder resists, buffer coat films, underfill materials, die bonding materials, semiconductor encapsulants, hole-filling resins, and component-embedding resins.

[0184] A preferred example is that the photosensitive film may be used for forming an insulating layer. A specific example is that the photosensitive film may be used for forming an insulating layer on a printed circuit board (a printed circuit board having a cured photosensitive resin composition layer as an insulating layer).

[0185] For example, a photosensitive film may be used for forming an interlayer insulating layer. Specifically, a photosensitive film may be used for forming the interlayer insulating layer of a printed circuit board that has a cured photosensitive resin composition layer as the interlayer insulating layer.

[0186] For example, a photosensitive film may be used for forming a plating. Specifically, a photosensitive film may be used for forming the insulating layer of a printed circuit board comprising an insulating layer containing a cured product of a photosensitive resin composition layer and a plating formed on that insulating layer.

[0187] For example, a photosensitive film may be used for forming a solder resist. Specifically, a photosensitive film may be used for forming a solder resist in a printed circuit board that has a cured photosensitive resin composition layer as the solder resist.

[0188] For example, a photosensitive film may be used to form a redistribution layer in a wafer-level package. Specifically, a photosensitive film may be used to form a redistribution layer in a wafer-level package that includes a cured photosensitive resin composition layer as the redistribution layer.

[0189] For example, a photosensitive film may be used to form a redistribution layer in a fan-out wafer-level package. Specifically, a photosensitive film may be used to form a redistribution layer in a fan-out wafer-level package that includes a cured photosensitive resin composition layer as the redistribution layer.

[0190] For example, a photosensitive film may be used to form a rewiring layer in a fan-out panel-level package. Specifically, a photosensitive film may be used to form a rewiring layer in a fan-out panel-level package that includes a cured photosensitive resin composition layer as the rewiring layer.

[0191] For example, a photosensitive film may be used for a buffer coat. Specifically, a photosensitive film may be used to form a buffer coat film in a semiconductor device that includes a cured photosensitive resin composition layer as the buffer coat film.

[0192] For example, a photosensitive film may be used to form an insulating layer of a display. Specifically, a photosensitive film may be used to form an insulating layer in a display that has a cured photosensitive resin composition layer as the insulating layer.

[0193] [Laminated structure] The laminate of the present invention comprises a first photosensitive resin composition layer made of a first photosensitive resin composition, and a second photosensitive resin composition layer made of a second photosensitive resin composition provided on the first photosensitive resin composition layer. The first and second photosensitive resin compositions and the first and second photosensitive resin composition layers in the laminate are as described above.

[0194] The laminate is obtained by peeling off the support and protective film after completing steps (1) to (3) in the above-described method for manufacturing the photosensitive film. The method for peeling off the support and other components can be carried out by known methods.

[0195] [Semiconductor package substrates] The semiconductor package substrate comprises an insulating layer formed from a cured product of the photosensitive resin composition layer described above (cured products of the first and second photosensitive resin compositions). Therefore, the insulating layer includes a cured product of the photosensitive resin composition layer, preferably containing only a cured product of the photosensitive resin composition layer. When the photosensitive film described above is used, the insulating layer can be formed to be thick. The specific range of the insulating layer's thickness may be the same as the range of the photosensitive resin composition layer's thickness. This insulating layer is preferably used as a redistribution layer, an interlayer insulating layer, a buffer coat film, or a solder resist.

[0196] In the first example, the semiconductor package substrate can be manufactured using the above-mentioned photosensitive film, and the cured product of the photosensitive resin composition layer is used as an insulating layer. Specifically, the method for manufacturing the semiconductor package substrate according to the first example is: (I) A step of laminating a photosensitive resin composition layer of a photosensitive film onto a circuit board, (II) A step of irradiating the photosensitive resin composition layer with an active light, (III) A step of developing the photosensitive resin composition layer, It includes them in this order.

[0197] <Process (I)> In step (I), the circuit board and the second photosensitive resin composition layer in the photosensitive resin composition layer are laminated together.

[0198] Examples of circuit boards include substrates equipped with support substrates such as glass epoxy substrates, metal substrates, polyester substrates, polyimide substrates, BT resin substrates, and thermosetting polyphenylene ether substrates. Here, a circuit board refers to a substrate on which a patterned conductive layer (circuit) is formed on one or both sides of the support substrate as described above. Furthermore, a multilayer printed wiring board, which is formed by alternately laminating conductive layers and insulating layers, is also included in the definition of a circuit board in which one or both sides of the outermost layer of the multilayer printed wiring board are patterned conductive layers (circuits). The surface of the conductive layer may be pre-treated with a roughening treatment such as blackening or copper etching.

[0199] The lamination of the photosensitive film and the circuit board is carried out so that the second photosensitive resin composition layer is bonded to the circuit board. If the photosensitive film has a protective film, the protective film is removed before lamination. The photosensitive film may be laminated to one side of the circuit board or to both sides. For example, the photosensitive film and the circuit board may be preheated as needed, and the lamination may be carried out by pressing the photosensitive film onto the circuit board while applying pressure and heating it. In the case of the photosensitive film, a method of lamination to the circuit board under reduced pressure by vacuum lamination is preferably used.

[0200] The lamination conditions are not particularly limited. For example, the bonding temperature (laminating temperature) is preferably 50°C to 120°C, and the bonding pressure is preferably 1 kgf / cm². 2 ~11 kgf / cm² 2 (9.8 × 10 4 N / m 2 ~107.9×10 4 N / m 2 The lamination process is preferably carried out under reduced pressure, with a pressing time of 5 to 300 seconds and an air pressure of 20 mmHg (26.7 hPa) or less. The lamination process may be batch-type or continuous-type using rolls. The vacuum lamination method can be carried out using a commercially available vacuum laminator. Examples of commercially available vacuum laminators include the vacuum applicator manufactured by Nikko Materials, the vacuum pressure laminator manufactured by Meiki Seisakusho, the roll-type dry coater manufactured by Hitachi Industries, and the vacuum laminator manufactured by Hitachi AIC.

[0201] <Process (II)> After a photosensitive resin composition layer is provided on the circuit board, an exposure process is then performed in which an active light is irradiated onto a predetermined portion of the photosensitive resin composition layer through a mask pattern. Examples of active light include ultraviolet light, visible light, electron beams, and X-rays, with ultraviolet light being particularly preferred. The irradiation dose of ultraviolet light is typically 10 mJ / cm². 2 ~1000 mJ / cm 2There are two exposure methods: contact exposure, in which the mask pattern is placed in close contact with the circuit board, and non-contact exposure, in which parallel light is used for exposure without contact. Either method can be used.

[0202] In step (II), a via pattern such as a circular hole pattern may be used as the mask pattern. For example, a mask pattern capable of forming a latent image of a via hole having a desired via diameter (aperture diameter) may be used. The via diameter (aperture diameter) is preferably 100 μm or less, more preferably 90 μm or less, and even more preferably 80 μm or less. The lower limit is not particularly limited, but may be 0.1 μm or more, 0.5 μm or more, etc.

[0203] After exposure, heat treatment may be performed as needed. Heat treatment can rapidly reduce the solubility of the exposed portion (exposed area) of the photosensitive resin composition layer in the developer.

[0204] <Process (III)> After the exposure process, a developing process is performed in which the unexposed parts (non-exposed areas) of the photosensitive resin composition layer are removed with a developer solution. This creates holes in the photosensitive resin composition layer, allowing the desired pattern to be obtained. Development is usually performed by wet development.

[0205] In the wet development described above, a safe, stable, and easy-to-handle developer solution is typically used, such as an alkaline solution, aqueous developer, or organic solvent. Furthermore, known development methods such as spraying, swirling immersion, brushing, and scraping are appropriately employed.

[0206] Examples of alkaline aqueous solutions used as developing solutions include aqueous solutions of alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, and potassium hydroxide; carbonates or bicarbonates such as sodium carbonate and sodium bicarbonate; alkali metal phosphates such as sodium phosphate and potassium phosphate; alkali metal pyrophosphates such as sodium pyrophosphate and potassium pyrophosphate; and aqueous solutions of organic bases that do not contain metal ions, such as tetraalkylammonium hydroxide. An aqueous solution of tetramethylammonium hydroxide (TMAH) is preferred because it does not contain metal ions and does not affect semiconductor chips.

[0207] These alkaline aqueous solutions may contain additives such as surfactants and defoamers to improve the developing effect. The pH of the alkaline aqueous solution is preferably in the range of 8 to 12, and more preferably in the range of 9 to 11. The base concentration of the alkaline aqueous solution is preferably 0.1% to 10% by mass. The temperature of the alkaline aqueous solution can be appropriately selected according to the developability of the photosensitive resin composition layer, and is preferably 20°C to 50°C.

[0208] Organic solvents used as developing solutions include, for example, acetone, ethyl acetate, alkoxyethanol having alkoxy groups with 1 to 4 carbon atoms, ethyl alcohol, isopropyl alcohol, butyl alcohol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, cyclopentanone, and cyclohexanone.

[0209] The concentration of such organic solvents is preferably 2% to 90% by mass relative to the total volume of the developer. The temperature of such organic solvents can be adjusted according to the developing properties. Furthermore, such organic solvents can be used alone or in combination of two or more types. Examples of organic solvent-based developers used alone include 1,1,1-trichloroethane, N-methylpyrrolidone, N,N-dimethylformamide, cyclopentanone, cyclohexanone, methyl isobutyl ketone, and γ-butyrolactone.

[0210] In pattern formation, two or more development methods may be used in combination as needed. Development methods include the dip method, battle method, spray method, high-pressure spray method, brushing, and slapping, with the high-pressure spray method being preferable for improving resolution. When using the spray method, a spray pressure of 0.05 MPa to 0.3 MPa is preferred.

[0211] <Thermosetting (post-bake) process> After the completion of step (III) above, a thermosetting (post-bake) step is performed as necessary. Although the photosensitive resin composition layer may harden during steps (I) to (III) above, the thermosetting step further hardens the photosensitive resin composition layer, making it possible to obtain an insulating layer with superior mechanical strength. Examples of thermosetting steps include heating using a clean oven. The atmosphere during thermosetting may be air or an inert gas atmosphere such as nitrogen. The heating conditions can be appropriately selected depending on factors such as the type and content of resin components in the first and second photosensitive resin composition layers. The specific heating conditions are preferably selected in the range of 150°C to 300°C for 20 to 300 minutes, and more preferably in the range of 170°C to 250°C for 30 to 240 minutes.

[0212] <Optional steps> A method for manufacturing a semiconductor package substrate may include, after forming an insulating layer as a cured photosensitive resin composition layer, a drilling step and a desmear step. These steps may be carried out according to various methods known to those skilled in the art that are used in the manufacture of semiconductor package substrates.

[0213] After forming the insulating layer, via holes and through holes may be formed in the insulating layer on the circuit board, if desired. The drilling process can be carried out by known methods such as drills, lasers, and plasma, or a combination of these methods as needed. Among these, drilling using lasers such as carbon dioxide lasers and YAG lasers is preferred.

[0214] The desmearing process is a process of applying a desmear treatment to the insulating layer. Generally, resin residue (smear) adheres to the inside of openings such as via holes and through holes formed in the drilling process. Since such smear can cause electrical connection failures, it is preferable to perform a smear removal treatment (desmearing treatment) in this process.

[0215] Desmear treatment may be carried out by dry desmear treatment, wet desmear treatment, or a combination thereof.

[0216] Examples of dry desmearing processes include plasma-based desmearing. Plasma-based desmearing can be performed using commercially available plasma desmearing equipment. Among commercially available plasma desmearing equipment, examples suitable for semiconductor package substrate manufacturing include microwave plasma equipment manufactured by Nissin Corporation and atmospheric pressure plasma etching equipment manufactured by Sekisui Chemical Co., Ltd.

[0217] Examples of wet desmear treatments include desmear treatment using an oxidizing agent solution. When desmear treatment is performed using an oxidizing agent solution, it is preferable to perform swelling treatment with a swelling solution, oxidation treatment with an oxidizing agent solution, and neutralization treatment with a neutralizing solution in this order. Examples of swelling solutions include "Swelling-Dip-Securigant P" and "Swelling-Dip-Securigant SBU" manufactured by Atotec Japan. The swelling treatment is preferably performed by immersing a substrate with openings such as via holes in a swelling solution heated to 60°C to 80°C for 5 to 10 minutes. As an oxidizing agent solution, an alkaline permanganate aqueous solution is preferred, for example, a solution obtained by dissolving potassium permanganate or sodium permanganate in an aqueous solution of sodium hydroxide. The oxidation treatment with the oxidizing agent solution is preferably performed by immersing the substrate after swelling treatment in an oxidizing agent solution heated to 60°C to 80°C for 10 to 30 minutes. Examples of commercially available alkaline permanganate aqueous solutions include "Concentrate Compact CP" and "Dozing Solution Securigant P" from Atotech Japan. Neutralization treatment with a neutralizing solution is preferably carried out by immersing the oxidized substrate in a neutralizing solution at 30°C to 50°C for 3 to 10 minutes. An acidic aqueous solution is preferred as the neutralizing solution, and an example of a commercially available product is "Reduction Solution Securigant P" from Atotech Japan.

[0218] When combining dry desmearing and wet desmearing, the dry desmearing may be performed first, or the wet desmearing may be performed first.

[0219] Regardless of whether the insulating layer is formed as a redistribution layer, an interlayer insulating layer, or a solder resist, a drilling process and a desmear process may be performed after the thermal curing process. Furthermore, in the semiconductor package substrate manufacturing method, a conductor layer formation process may be performed in addition.

[0220] The conductor layer formation process is a process of forming a conductor layer on an insulating layer. The conductor layer may be formed by sputtering after the insulating layer is formed. Alternatively, the conductor layer may be formed by a combination of electroless plating and electrolytic plating. Furthermore, a plating resist with a pattern inverse to that of the conductor layer may be formed, and the conductor layer may be formed by electroless plating alone. As a method for subsequent pattern formation, for example, subtractive methods and semi-additive methods known to those skilled in the art can be used.

[0221] The semiconductor package substrate according to the second example can be manufactured using the first and second photosensitive resin compositions, and the cured products of the first and second photosensitive resin compositions are used as insulating layers. The first and second photosensitive resin compositions are as described above. Specifically, the method for manufacturing the semiconductor package substrate according to the second example is as follows: (a) A step of applying and drying a second photosensitive resin composition onto a circuit board to form a second photosensitive resin composition layer, (b) A step of applying and drying the first photosensitive resin composition onto the second photosensitive resin composition layer to form the first photosensitive resin composition layer, (c) A step of irradiating the first and second photosensitive resin composition layers with active light, (d) A step of developing the first and second photosensitive resin composition layers, It includes them in this order.

[0222] In step (a), a second resin varnish containing the second photosensitive resin composition is directly applied to the circuit board and dried to form a second photosensitive resin composition layer on the circuit board. The second resin varnish is as described above.

[0223] The second method of applying the resin varnish is the same as the method of applying the second resin varnish in the method of manufacturing a photosensitive film.

[0224] In step (b), a first resin varnish containing the first photosensitive resin composition is applied to the first photosensitive resin composition layer and dried to form the first photosensitive resin composition layer on the second photosensitive resin composition layer. The first resin varnish is as described above.

[0225] The first method of applying the resin varnish is the same as the first method of applying the resin varnish in the method of manufacturing a photosensitive film.

[0226] Process (c) is the same as process (II). Process (d) is the same as process (III).

[0227] The semiconductor package substrate according to the third example can be manufactured using the above-mentioned photosensitive film or the first and second photosensitive resin compositions, and the cured product of the photosensitive resin composition layer is used as a redistribution forming layer. Specifically, the method for manufacturing the semiconductor package substrate according to the third example is: (A) A step of laminating a temporary fixing film onto the substrate, (B) A step of temporarily fixing the semiconductor chip onto a temporary fixing film, (C) A process of forming a encapsulation layer on a semiconductor chip, (D) Steps to peel off the substrate and temporary fixing film from the semiconductor chip, (E) A step of forming a rewiring layer as an insulating layer on the surface from which the substrate and temporary fixing film of the semiconductor chip have been peeled off. (F) A step of forming a redistribution layer as a conductor layer on a redistribution formation layer, and (G) A step of forming a solder resist layer on the redistribution layer, This includes the above. Furthermore, the method for manufacturing the semiconductor package substrate is (H) A process of dicing multiple semiconductor package substrates into individual semiconductor package substrates and separating them into individual pieces. It may include.

[0228] <Process (A)> Step (A) is a step of laminating a temporary fixing film onto the substrate. The lamination conditions for the substrate and the temporary fixing film are not particularly limited, but for example, the pressing temperature (laminating temperature) is preferably 70°C to 140°C, and the pressing pressure is preferably 1 kgf / cm². 2 ~11 kgf / cm² 2Preferably, the lamination is performed under reduced pressure, with a pressing time of 5 to 300 seconds and an air pressure of 20 mmHg or less. The lamination process may be batch-type or continuous-type using rolls. The vacuum lamination method can be carried out using a commercially available vacuum laminator. Examples of commercially available vacuum laminators include the vacuum applicator manufactured by Nikko Materials, the vacuum pressure laminator manufactured by Meiki Seisakusho, the roll-type dry coater manufactured by Hitachi Industries, and the vacuum laminator manufactured by Hitachi AIC.

[0229] Examples of substrates include silicon wafers, glass wafers, glass substrates, metal substrates such as copper, titanium, stainless steel, and cold-rolled steel sheets (SPCC), substrates such as FR-4 substrates which are made by impregnating glass fibers with epoxy resin and then heat-curing them, and substrates made of bismaleimide triazine resin such as BT resin.

[0230] The temporary fixing film can be made of any material that can be peeled off from the semiconductor chip and can temporarily fix the semiconductor chip. Examples of commercially available products include Nitto Denko's "Riva Alpha".

[0231] <Process (B)> Step (B) is a step of temporarily fixing semiconductor chips onto a temporary fixing film. Temporary fixing of semiconductor chips can be performed using equipment such as a flip-chip bonder or die bonder. The layout and number of semiconductor chips can be appropriately set according to the shape and size of the temporary fixing film, the number of semiconductor package substrates to be produced, etc. For example, semiconductor chips may be arranged in a matrix of multiple rows and multiple columns and then temporarily fixed.

[0232] <Process (C)> Step (C) is a step of forming a encapsulation layer on a semiconductor chip. The encapsulation layer can be made of any insulating material, and may be made of the first and / or second photosensitive resin composition described above. The encapsulation layer is usually formed by a method that includes the steps of forming an encapsulation resin composition layer on a semiconductor chip and thermal curing this resin composition layer to form a encapsulation layer.

[0233] The sealing resin composition layer is preferably formed by compression molding. In compression molding, the semiconductor chip and the sealing resin composition are typically placed in a mold, and pressure and, if necessary, heat are applied to the sealing resin composition within the mold to form a sealing resin composition layer that covers the semiconductor chip.

[0234] The specific operation of the compression molding method can be carried out as follows, for example: An upper mold and a lower mold are prepared as molds for compression molding. The encapsulating resin composition is applied to the semiconductor chip that has been temporarily fixed onto the temporary fixing film as described above. The semiconductor chip coated with the encapsulating resin composition is attached to the lower mold together with the substrate and the temporary fixing film. Then, the upper and lower molds are clamped together, and heat and pressure are applied to the encapsulating resin composition to perform compression molding.

[0235] Furthermore, the specific operation of the compression molding method may be as follows, for example: An upper mold and a lower mold are prepared as molds for compression molding. The sealing resin composition is placed on the lower mold. The semiconductor chip is attached to the upper mold together with the substrate and temporary fixing film. Then, the upper and lower molds are clamped together so that the sealing resin composition on the lower mold is in contact with the semiconductor chip attached to the upper mold, and heat and pressure are applied to perform compression molding.

[0236] The molding conditions vary depending on the composition of the sealing resin composition, and appropriate conditions can be adopted to achieve good sealing. For example, the mold temperature during molding is preferably a temperature at which the sealing resin composition exhibits excellent compression moldability, preferably 80°C or higher, more preferably 100°C or higher, particularly preferably 120°C or higher, preferably 200°C or lower, more preferably 170°C or lower, and particularly preferably 150°C or lower. The pressure applied during molding is preferably 1 MPa or higher, more preferably 3 MPa or higher, particularly preferably 5 MPa or higher, preferably 50 MPa or lower, more preferably 30 MPa or lower, and particularly preferably 20 MPa or lower. The curing time is preferably 1 minute or more, more preferably 2 minutes or more, particularly preferably 5 minutes or more, preferably 60 minutes or less, more preferably 30 minutes or less, and particularly preferably 20 minutes or lower. Typically, the mold is removed after the formation of the sealing resin composition layer. The mold may be removed before or after the heat curing of the sealing resin composition layer.

[0237] The compression molding method may also be performed by extruding the sealing resin composition filled in the cartridge into a lower mold.

[0238] <Process (D)> Step (D) is a step of peeling the substrate and temporary fixing film from the semiconductor chip. It is desirable to adopt an appropriate peeling method depending on the material of the temporary fixing film. Examples of peeling methods include peeling by heating, foaming, or expanding the temporary fixing film. Another example of a peeling method is peeling by irradiating the temporary fixing film with ultraviolet light through the substrate to reduce the adhesive strength of the temporary fixing film and then peeling it off.

[0239] In the method of peeling off a temporary fixing film by heating, foaming, or expanding it, the heating conditions are typically 100°C to 250°C for 1 to 90 seconds or 5 to 15 minutes. In the method of peeling off a temporary fixing film by reducing its adhesive strength through ultraviolet irradiation, the ultraviolet irradiation dose is typically 10 mJ / cm². 2 ~1000 mJ / cm 2 That is the case.

[0240] <Process (E)> Step (E) is a step of forming a redistribution-forming layer as an insulating layer on the surface from which the substrate and temporary fixing film of the semiconductor chip have been peeled off. The redistribution-forming layer may be formed using the photosensitive film described above or the first and second photosensitive resin compositions. The method for forming the redistribution-forming layer may include forming the photosensitive resin composition layer in the same manner as in step (I) in the first example, or it may include forming the photosensitive resin composition layer in the same manner as in steps (a) and (b) in the second example.

[0241] When forming a redistribution layer, via holes may be formed in the redistribution layer to connect the semiconductor chip and the redistribution layer.

[0242] Via holes can typically be formed by an exposure step in which an active light beam is irradiated onto the surface of a photosensitive resin composition layer for forming a redistribution layer through a mask pattern, and a development step in which unexposed areas that have not been irradiated with the active light beam are developed and removed. The amount and duration of irradiation of the active light beam can be appropriately set according to the photosensitive resin composition layer. Examples of exposure methods include contact exposure, in which the mask pattern is in close contact with the photosensitive resin composition layer during exposure, and non-contact exposure, in which the mask pattern is not in close contact with the photosensitive resin composition layer and parallel light beams are used for exposure. The exposure and development methods can be carried out as described in the first example.

[0243] The shape of the via hole is not particularly limited, but is generally circular (or nearly circular). The top diameter of the via hole is preferably 100 μm or less, more preferably 90 μm or less, even more preferably 80 μm or less, preferably 0.1 μm or more, preferably 0.5 μm or more, and more preferably 1.0 μm or more. Here, the top diameter of the via hole refers to the diameter of the via hole opening on the surface of the redistribution forming layer.

[0244] A photosensitive resin composition layer may be formed, and via holes may be formed as needed, after which a heat curing process may be carried out. The heat curing method may be as described in the first example.

[0245] <Process (F)> Step (F) is the step of forming a redistribution layer as a conductor layer on the redistribution formation layer. The method of forming the redistribution layer on the redistribution formation layer may be the same as the method of forming a conductor layer on the insulating layer in the first example. Alternatively, steps (E) and (F) may be repeated to alternately stack the redistribution layer and the redistribution formation layer (build-up).

[0246] <Process (G)> Step (G) is a step of forming a solder resist layer on the redistribution layer. Any insulating material can be used for the solder resist layer. Among these, photosensitive resins and thermosetting resins are preferred from the viewpoint of ease of manufacturing semiconductor package substrates. Alternatively, the first or second photosensitive resin composition described above may be used.

[0247] Furthermore, in step (G), bumping may be performed to form bumps as needed. Bumping can be performed by methods such as solder balls or solder plating. The formation of via holes in the bumping process can be done in the same way as in step (E).

[0248] The method for manufacturing a semiconductor package substrate may include step (H) in addition to steps (A) to (G). Step (H) is a step of dicing a plurality of semiconductor package substrates into individual semiconductor package substrates to form individual pieces. The method of dicing the semiconductor package substrates into individual semiconductor package substrates is not particularly limited.

[0249] [Semiconductor device] The semiconductor device comprises the semiconductor package substrate described above. Examples of semiconductor devices on which the semiconductor package substrate is mounted include various semiconductor devices used in electrical products (e.g., computers, mobile phones, smartphones, tablet devices, wearable devices, digital cameras, medical equipment, and televisions, etc.) and vehicles (e.g., motorcycles, automobiles, trains, ships, and aircraft, etc.). [Examples]

[0250] The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. In the following description, "parts" and "%" refer to "parts by mass" and "mass%" respectively, unless otherwise specified. Furthermore, the operations described below were carried out in ambient air at normal temperature and pressure (25°C and 1 atm), unless otherwise specified.

[0251] [Synthesis Example 1: Synthesis of Polymer A-1] Under a nitrogen atmosphere, 105.6 g of 5-(2,5-dioxotetrahydrofuryl)-3-methyl-3-cyclohexene-1,2-dicarboxylic acid anhydride (MCTC) and 500 g of γ-butyrolactone were dissolved in a 1 L separable flask. 104.3 g of 1-(4-aminophenyl)-1,3,3-trimethylindanamine (PIDA) was added, and the reaction was carried out at 50°C for 20 hours to obtain polyamic acid. 111.3 g of glycidyl methacrylate and 0.42 g of 4-methoxyphenol were added, and the reaction was carried out at 50°C for 20 hours to obtain a solution of polymer A-1 (solid content 33%), a polyimide precursor. The molecular weight of polymer A-1 was measured by gel permeation chromatography (in terms of standard polystyrene), and the weight-average molecular weight (Mw) was 16,000. The structural units of polymer A-1, a polyimide precursor, are shown below (where n is an integer between 5 and 200). [ka]

[0252] [Synthesis Example 2: Synthesis of Polymer A-2] 20.0 g (64.5 mmol) of oxydiphthalic anhydride was suspended in 140 mL of diglym while removing moisture in a drying reactor equipped with a stirrer, condenser, and flat-bottom joint with an internal thermometer. Subsequently, 16.8 g (129 mmol) of 2-hydroxyethyl methacrylate, 0.05 g of hydroquinone, 0.05 g of pure water, and 10.7 g (135 mmol) of pyridine were added, and the mixture was stirred at 60°C for 18 hours. The mixture was then cooled to -20°C, and 16.1 g (135.5 mmol) of thionyl chloride was added dropwise over 90 minutes. A white precipitate of pyridinium hydrochloride was obtained. The mixture was then warmed to room temperature and stirred for 2 hours, after which 9.7 g (123 mmol) of pyridine and 25 mL of N-methylpyrrolidone (NMP) were added to obtain a clear solution. Next, 11.8 g (58.7 mmol) of 4,4'-diaminodiphenyl ether dissolved in 100 mL of NMP was added dropwise to the resulting clear solution over 1 hour. Then, 5.6 g (17.5 mmol) of methanol and 0.05 g of 3,5-di-tert-butyl-4-hydroxytoluene were added, and the mixture was stirred for 2 hours. Next, polymer A-2, the polyimide precursor, was precipitated in 4 liters of water, and the water-polyimide precursor resin mixture was stirred at a speed of 500 rpm for 15 minutes. Polymer A-2 was obtained by filtration, stirred again in 4 liters of water for 30 minutes, and filtered again. Then, the obtained polymer A-2 was dried under reduced pressure at 45°C for 3 days. The weight-average molecular weight of the obtained polymer A-2 was 24,800, and the number-average molecular weight was 10,500. The structural units of polymer A-2, the polyimide precursor, are shown below. [ka]

[0253] [Synthesis Example 3: Synthesis of Polyimide A-3] Under a nitrogen atmosphere, 104 g of 2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride (BPADA) was dissolved in 383 g of γ-butyrolactone in a 1 L separable flask. 60.1 g of 5,5'-methylenebis(2-aminobenzoic acid) (MBAA) was added, and the reaction was carried out at 50°C for 20 hours to obtain polyamic acid (polyimide precursor). 55 g of toluene was added, and azeotropic dehydration was carried out for 5 hours. The reaction solution was then heated to 204°C to remove the toluene and obtain a polyimide solution. After cooling to room temperature, 59.6 g of glycidyl methacrylate and 0.45 g of 4-methoxyphenol were added, and the reaction was carried out at 100°C for 5 hours to obtain polyimide solution (A-3) (solid content 33%). The molecular weight of the polyimide solution (A-3) was measured by gel permeation chromatography (on a standard polystyrene basis), and the weight-average molecular weight (Mw) was found to be 30,000. The structural units of polymer A-3, which is a polyimide, are shown below. [ka]

[0254] [Examples 1-13 and Comparative Examples 1-4] (Preparation of the first and second photosensitive resin compositions) The reagents shown in the table below were mixed in the amounts (parts by mass) shown in the table and stirred using a high-speed rotary mixer to prepare a varnish-like first photosensitive resin composition. A varnish-like second photosensitive resin composition was prepared in the same manner as the first photosensitive resin composition. In the table, the amount of each reagent represents the amount of solids in each reagent, with 100 parts by mass of the solids (polyimide precursor) contained in the (A) solution prepared in the above synthesis example. In the table, the solids content represents the content when (A) is converted to 100 parts by mass. The amount of component (B-1) added represents the content of component (B-1) in the photosensitive resin composition when component (A) is present in 100 parts by mass; the amount of component (B-2) added represents the content of component (B-2) in the photosensitive resin composition when component (A) is present in 100 parts by mass; and the amount of component (B) added represents the content of component (B) in the photosensitive resin composition when component (A) is present in 100 parts by mass. Polymer A-2 was used as a γ-butyrolactone solution with a solid content of 33%.

[0255] (Manufacturing of photosensitive film) A PET film (Toray Industries' "Lumirror T6AM," 38 μm thick) was prepared as a support. The first photosensitive resin composition prepared in each example and comparative example was uniformly applied to the support using a die coater so that the thickness of the photosensitive resin composition layer after drying was 30 μm, and the first photosensitive resin composition layer was formed by drying at 80°C to 120°C for 6 minutes. This is referred to as photosensitive sheet A.

[0256] Similarly, a PET film (Toray Industries' "Lumirror T6AM," 38 μm thick) was prepared as a support. The second photosensitive resin composition prepared in each example and comparative example was uniformly applied to the support using a die coater so that the thickness of the photosensitive resin composition layer after drying was 30 μm, and dried at 80°C to 120°C for 6 minutes to form the second photosensitive resin composition layer. This is referred to as photosensitive sheet B.

[0257] To bond the first and second photosensitive resin composition layers, photosensitive sheets A and B were laminated using a manual vacuum pressure laminator (Nikko Materials Co., Ltd., diaphragm laminator "V-160") to obtain a 60 μm thick, two-layer photosensitive resin composition layer. The bonding conditions were: vacuuming time 30 seconds, bonding temperature 60°C, bonding pressure 0.7 MPa, and pressing time 180 seconds.

[0258] (Measurement of absorbance) Photosensitive sheets A and B were prepared (only photosensitive sheet B was prepared for Comparative Example 1). The first and second photosensitive resin composition layers of photosensitive sheets A and B were cut into 3 cm squares, and the total light transmittance was measured at three points using the PET film "Lumirror T6AM" with the reference as the support. The thickness of the sheet used for measurement was measured, and the average of the three transmittances was converted to a thickness of 30 μm and taken as the absorbance. Here, the absorbance of the first and second photosensitive resin composition layers was calculated by measuring the total light transmittance T (%) at a wavelength of 365 nm for each photosensitive resin composition layer and using the following formula. Absorbance=2-log(T)

[0259] [Table 1] [Table 2]

[0260] Details of each reagent in the table are as follows: (A) component • Polymer A-1: ​​Polymer A-1 synthesized in Synthesis Example 1 • Polymer A-2: Polymer A-2 synthesized in Synthesis Example 2 • Polymer A-3: Polymer A-3 synthesized in Synthesis Example 3 (B) Component (B-1) Component • Irgacure OXE02: Oxime ester-based photoradical generator, photopolymerization initiator shown in the following formula (BASF's "Irgacure OXE02") [ka] • Irgacure OXE01: Oxime ester-based photoradical generator, photopolymerization initiator shown in the following formula (BASF's "Irgacure OXE01") [ka] (B-2) Component • Omnirad819: (Acylphosphine-based photoradical generator, manufactured by IGM, "Omnirad819") • OmniradTPO: (Acylphosphine-based photoradical generator, manufactured by IGM, "OmniradTPO") (C) Component • TMPT: A photocrosslinking agent with four or fewer functionalities as shown in the formula below (TMPT, manufactured by Shin-Nakamura Chemical Industry Co., Ltd.) [ka] • DPHA: Dipentaerythritol hexaacrylate, manufactured by Nippon Kayaku Co., Ltd., 5 or 6 functional. • A-TMPT: A photocrosslinking agent with four or fewer functionalities as shown in the formula below (A-TMPT, manufactured by Shin-Nakamura Chemical Industry Co., Ltd.) [ka] • M-933: Dipentaerythritol tetraacrylate, manufactured by Toagosei Co., Ltd.

[0261] <Evaluation of Limit Resolution> A copper plating layer with a thickness of 5 μm was deposited on a silicon wafer. The substrate was roughened with a 1% hydrochloric acid aqueous solution for 60 seconds. The second photosensitive resin composition layer of the photosensitive film was placed on the substrate so that it was in contact with the surface of the copper layer. Lamination was performed using a vacuum laminator (Meiki Seisakusho Co., Ltd., MVLP5000 / 600-IIW) to form a laminate in which the copper plating, the second photosensitive resin composition layer, the first photosensitive resin composition layer, and the support were laminated in this order (Comparative Example 1 was a laminate in which the copper plating, the second photosensitive resin composition layer, and the support were laminated in this order). The bonding conditions were: vacuuming time 30 seconds, bonding temperature 80°C, bonding pressure 0.7 MPa, and pressing time 30 seconds. After standing at room temperature for 30 minutes, the support was peeled off the laminate. The laminate from which the support had been peeled off was exposed to ultraviolet light (wavelength 365 nm, intensity 40 mW / cm²). 2 Exposure was performed using ). The exposure dose was 200 mJ / cm². 2 The range was set. For the exposure pattern, a quartz glass mask was used to draw circular holes (vias) with aperture diameters of 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, and 70 μm. After standing at room temperature for 5 minutes, a heat treatment was performed at 100°C for 3 minutes. The entire surface of the photosensitive resin composition layer on the laminate was spray-developed with cyclopentanone at 23°C at a spray pressure of 0.1 MPa for an optimal time between 30 and 100 seconds, followed by a spray rinse with propylene glycol monomethyl ether acetate at a spray pressure of 0.1 MPa for 30 seconds. The photosensitive resin composition layer was further cured by a heat treatment at 180°C for 180 minutes. This is referred to as the evaluation sample. The diameter of the bottom of the vias of this evaluation sample was observed with a scanning electron microscope (SEM) (magnification 1000x), and the smallest size that could be opened without residue or peeling was defined as the limit aperture via. The following evaluation criteria were used for evaluation. ○: The aspect ratio of the limiting via diameter (film thickness (μm) / via diameter (μm)) is 1.0 or greater. △: The aspect ratio (film thickness (μm) / via diameter (μm)) of the critical via diameter is 0.5 or greater and less than 1.0. ×: The aspect ratio (film thickness (μm) / via diameter (μm)) of the critical via diameter is less than 0.5.

[0262] Additionally, the exposure dose is 300 mJ / cm². 2, 400 mJ / cm 2 , and 500 mJ / cm 2 The same evaluation was performed when the range was set accordingly.

[0263] <Evaluation of cross-sectional shape (undercut resistance)> For the observation of undercuts, evaluation samples were observed using a SEM (Scanning Electron Microscope) with an aperture diameter of 70 μm (magnification 2000x). The radius of the top (μm) and bottom (μm) of the via cross-section were measured using the SEM, and the difference between the bottom radius and the top radius (bottom radius - top radius) was calculated. This value was defined as the undercut and evaluated according to the following evaluation criteria. ◎: No undercut. ○: Undercut is less than 2 μm. △: Undercut is between 2μm and 4μm. ×: The undercut is greater than 4 μm, or vias with an opening diameter of 70 μm are not open.

[0264] <Evaluation of adhesion> A copper plating layer with a thickness of 5 μm was laminated onto a silicon wafer. The substrate was roughened with a 1% hydrochloric acid aqueous solution for 60 seconds. The second photosensitive resin composition layer of the photosensitive film was placed on the substrate so that it was in contact with the surface of the copper layer. Lamination was performed using a vacuum laminator (Nikko Materials Co., Ltd., VP160) to form a laminate in which the copper plating, the second photosensitive resin composition layer, the first photosensitive resin composition layer, and the support were laminated in this order. The bonding conditions were a vacuum time of 30 seconds, a bonding temperature of 60°C, a bonding pressure of 0.7 MPa, and a bonding time of 30 seconds. After standing at room temperature for 30 minutes, the support was peeled off the laminate. The laminate from which the support had been peeled off was exposed to ultraviolet light (wavelength 365 nm, intensity 40 mW / cm²). 2 Exposure was performed using ). The exposure dose was 200 mJ / cm². 2The range was set. For the exposure pattern, a quartz glass mask was used to draw circular holes (vias) with an aperture diameter of 70 μm. After standing at room temperature for 5 minutes, a heat treatment was performed at 100°C for 3 minutes. On the entire surface of the photosensitive resin composition layer on the laminate, cyclopentanone at 23°C was spray-developed at a spray pressure of 0.1 MPa for an optimal time between 30 and 100 seconds as the developer, and then propylene glycol monomethyl ether acetate was spray-rinsed at a spray pressure of 0.1 MPa for 30 seconds. Further heat treatment was performed at 170°C for 180 minutes to cure the photosensitive resin composition layer. The diameter of the bottom of the vias was observed using SEM to check the cross-section of the 70 μm circular holes (magnification 2000x) to confirm whether or not there was delamination between the substrate and the photosensitive resin composition layer of the photosensitive film (hereinafter, delamination between the substrate and the photosensitive resin composition layer of the photosensitive film may be called haloing). When haloing was observed, the distance of peeling from the side of the via was measured and defined as the haloing distance, which was then evaluated according to the following criteria. ◎: No Halloween. ○: Haloing distance is less than 2 μm. △: Haloing distance is between 2 μm and 4 μm. ×: The haloing distance is greater than 4 μm, or vias with a via diameter of 70 μm are not open.

[0265] [Table 3] [Table 4]

Claims

1. Support and A photosensitive film comprising a photosensitive resin composition layer provided on a support, The photosensitive resin composition layer comprises a first photosensitive resin composition layer made of a first photosensitive resin composition, and a second photosensitive resin composition layer made of a second photosensitive resin composition provided on the first photosensitive resin composition layer, in this order from the support side. The first and second photosensitive resin compositions are, (A) One or more resins selected from the group consisting of polyimides and polyimide precursors, (B) Photoradical generator, and (C) Contains a photocrosslinking agent, A photosensitive film in which the difference between the absorbance of the second photosensitive resin composition layer at a wavelength of 365 nm and the absorbance of the first photosensitive resin composition layer at a wavelength of 365 nm (absorbance of the second photosensitive resin composition layer at a wavelength of 365 nm - absorbance of the first photosensitive resin composition layer at a wavelength of 365 nm) is 0.05 or more and 0.5 or less.

2. The photosensitive film according to claim 1, wherein component (A) contains a structural unit represented by the following formula (A-1). 【Chemistry 1】 (In the formula, A independently represents a tetravalent organic group, B represents a divalent organic group, and R １ and R ２ Each of these independently represents a hydrogen atom or a monovalent organic group.

3. R in equation (A-1) １ and R ２ The photosensitive film according to claim 2, wherein each of the groups is independently at least one of which is a radical-reactive group.

4. The photosensitive film according to claim 3, wherein each radical-reactive group is independently represented by the following formula (A-2). 【Chemistry 2】 (In equation (A-2), R ４ａ , R ５ａ and R ６ａ Each of the following independently represents a hydrogen atom or an aliphatic hydrocarbon group having 1 to 3 carbon atoms, and X represents a divalent organic group. * represents a bond.

5. Component (B) comprises (B-1) a highly reactive photoradical generator and (B-2) a photoradical generator with excellent deep curing properties. Component (B-1) contains an oxime ester structure, The photosensitive film according to claim 1, wherein component (B-2) has a maximum absorption value in the wavelength range of 340 nm to 420 nm, or has an absorption coefficient of 4000 ml / gcm or less at a wavelength of 365 nm.

6. The photosensitive film according to claim 1, wherein the content of component (B) in the first photosensitive resin composition is less than the content of component (B) in the second photosensitive resin composition.

7. The photosensitive film according to claim 1, wherein the content of component (B) in the first photosensitive resin composition is 0.03 parts by mass or more and 5 parts by mass or less per 100 parts by mass of component (A) in the first photosensitive resin composition.

8. The photosensitive film according to claim 1, wherein the content of component (B) in the second photosensitive resin composition is 0.05 parts by mass or more and 8 parts by mass or less per 100 parts by mass of component (A) in the second photosensitive resin composition.

9. The photosensitive film according to claim 1, wherein the absorbance of the first photosensitive resin composition layer at a wavelength of 365 nm is 0.2 or more and 1.5 or less.

10. The photosensitive film according to claim 1, wherein the absorbance of the second photosensitive resin composition layer at a wavelength of 365 nm is 0.3 or more and 1.5 or less.

11. When the non-volatile components of the first photosensitive resin composition are 100% by mass, the content of the component (B-1) in the first photosensitive resin composition is b １－１ is defined as b ２－１ in the second photosensitive resin composition. When b １－１ / b ２－１ is 0.1 or more and 3 or less, the photosensitive film according to claim 5

12. The thickness of the photosensitive resin composition layer is 40 μm or more. The photosensitive film according to claim 1.

13. A semiconductor package substrate comprising an insulating layer containing a cured product of a photosensitive resin composition layer of a photosensitive film according to any one of claims 1 to 12.

14. A semiconductor device comprising a semiconductor package substrate as described in claim 13.

15. A step of laminating a photosensitive resin composition layer of a photosensitive film according to any one of claims 1 to 12 onto a circuit board, A step of irradiating a photosensitive resin composition layer with active light, A method for manufacturing a semiconductor package substrate, comprising the step of developing a photosensitive resin composition layer.

16. A step of applying a second photosensitive resin composition onto a circuit board to form a second photosensitive resin composition layer, A step of applying a first photosensitive resin composition onto a second photosensitive resin composition layer to form a first photosensitive resin composition layer, A step of irradiating the first and second photosensitive resin composition layers with active light, A method for manufacturing a semiconductor package substrate, comprising the step of developing first and second photosensitive resin composition layers, The first and second photosensitive resin compositions are (A) One or more resins selected from the group consisting of polyimides and polyimide precursors, (B) Photoradical generator, and (C) Each contains a photocrosslinking agent, A method for manufacturing a semiconductor package substrate, wherein the difference between the absorbance of the first photosensitive resin composition layer at a wavelength of 365 nm and the absorbance of the second photosensitive resin composition layer at a wavelength of 365 nm (absorbance of the second photosensitive resin composition layer at a wavelength of 365 nm - absorbance of the first photosensitive resin composition layer at a wavelength of 365 nm) is 0.05 or more and 0.5 or less.

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